


Hindsight

by Amethystina



Category: Marvel Cinematic Universe
Genre: Alternate Universe, Angst, Fluff, Grief/Mourning, Happy Ending, ImagineTonyandBucky Prompt Fill, M/M, Science Fiction, So blame Weir if anything is inaccurate, The science is stolen from the book, doctor bucky, perceived character death, survivor's guilt, the martian au
Language: English
Status: Completed
Published: 2017-06-18
Updated: 2017-07-05
Packaged: 2018-11-15 14:02:31
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 31,632
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11232525
Author URL: https://archiveofourown.org/users/Amethystina/pseuds/Amethystina
Summary: Ever since he was a little boy, Bucky has dreamed of becoming an astronaut together with Steve, and he can hardly believe their luck when both of them are picked for the Ares 3 crew — the third expedition sent to explore Mars. It is, quite literally, a dream come true.Things get complicated when Bucky finds himself inconveniently attracted to their mechanical engineer, however. Tony Stark is funny, competent, and absolutely captivating, but considering NASA's strict non-fraternization policy, Bucky knows it's better to keep his interest to himself — at least until they return to Earth. He can wait.Not once does Bucky consider the possibility that all of them might not make it back alive, or just how much he'll come to regret not acting when he had the chance.





	1. The Beginning

**Author's Note:**

> _**Prompt by Anonymous:** The Martian AU - Bucky, crew doctor, overwhelmed with guilt because he's the one that proclaimed Stark dead which led to Captain Rogers making the decision to leave Stark behind._
> 
> I LOVE _The Martian_ so when I found this prompt available to us [ImagineTonyandBucky](http://imaginetonyandbucky.tumblr.com/) authors, I just couldn't help myself. I based this fic off the book rather than the movie (due to slight differences at the end) but I think you should be able to read it even if you're not familiar with the source material.
> 
> I want to thank [surgicalstainless](http://archiveofourown.org/users/surgicalstainless) for helping me with the brainstorming (specifically who to include in the crew and what roles to give them) and for betaing the first three chapters. [Potrix](http://archiveofourown.org/users/potrix) also offered some well-needed encouragement and beta reading, for which I am extremely grateful <3 And, finally, a massive, massive thank you to [Shi_Toyu](http://archiveofourown.org/users/Shi_Toyu) for reading through the whole thing despite not having read the book or seen the movie, and for correcting my mistakes along the way. Thank you <3
> 
> Now buckle up, my lovelies! This one will hurt.

 

* * *

 

"STARK!"

Bucky was startled by Romanoff's shout over the comms channel. He had never heard her sound so frightened.

"What happened?" Steve asked sharply. The Martian sandstorm was roaring around them, fierce enough to turn each step of the evacuation into a struggle — only made worse by their bulky EVA suits. The wind was whipping up enough sand that Steve was the only one Bucky could see clearly.

"Something hit him." Romanoff's words were clipped and efficient, but that only made her underlying fear more apparent. "I don't know what. He got thrown off course — I can't see him."

"Stark, report," Steve demanded, voice tight.

Silence.

This couldn't be happening.

"Stark, report!" Steve turned, facing the way they had come. Bucky couldn't see his expression thanks to the reflective glass of the helmet, but Steve's anxiety bled through the terse command.

Bucky pushed back the panic, trying desperately to remember procedure. He was supposed to be trained for this, but he found it increasingly difficult to breathe around the tightness in his chest.

"He's offline," Bucky said, willing his voice to remain stable as he looked at his arm computer. "His... his decompression alarm went off, before we lost contact."

Decompression on the surface of Mars was a death sentence — it only took seconds, much less than a minute.

Seconds they didn't have. Seconds that might already have passed.

Bucky felt his stomach drop, and dread lodged in his throat.

"Which direction did he go?" Steve asked.

Bucky could barely hear him over the roaring in his ears.

"West," Romanoff replied.

"Barton, get to the MAV, prepare for launch," Steve ordered. "Everyone else, lock on to Romanoff. We need to find Stark — line up and walk slowly, heading west."

They hurried to obey, Thor on Bucky's left and Steve on his right. Bucky stumbled in the harsh wind, gaze aimed at the ground, hoping to see some kind of sign of their missing crewmate. His heartbeats echoed painfully loud in his ears, his body moving on autopilot. All thoughts seemed to have fled, slipping through his fingers — all but one.

_They had to find Tony._

Each careful step was made more difficult by the wind and the sand, and the tense silence that had settled over the channel only made the knot in Bucky's chest grow tighter. Fear hung so thick that Bucky could almost taste it on his tongue.

"Commander." Barton's voice rang out clear over the comms; he must have reached their transport. "The winds are too strong. The shuttle is tilting seven degrees. It'll tip at 12.3, and if it does, we'll never be able to take off."

They would be stuck on Mars. If they continued to search for Tony, none of them might ever leave the planet — at least not alive.

"Copy that," Steve replied. Bucky recognized the determination in his voice — Steve hadn't given up yet. "Continue prepping for launch, Barton."

"Will do," Barton shot back. For once, Steve didn't comment on Barton's habit of not following proper comms procedure.

Bucky's legs felt heavy and shaky, but he kept walking, as did the others. He wasn't sure if Thor had ever been this quiet before, at least not during the years Bucky had known him.

"Commander," Romanoff said, "Stark's bio-monitor sent a fractured information packet before he went offline. I managed to retrieve the raw data in plain text."

"Read it," Bucky demanded, surprised by his own harshness.

"BP 0, PR 0, TP 36.1," Romanoff replied. "I couldn't get more."

Bucky faltered. He couldn't breathe, sudden grief squeezing his chest.

"Bucky?" It was Steve's turn to abandon protocol — on comms they were Commander Rogers and Doctor Barnes, not Steve and Bucky.

Somehow, Bucky managed to make himself form words. "Blood pressure zero, pulse rate zero, temperature normal," he reported in a monotone.

There was only one way to interpret those numbers, though Bucky tried his damndest to deny it.

"If his temperature is normal—" Thor began, only to be interrupted by Romanoff.

"It takes a while for a body to cool." Her words were flat and jarring, but Bucky had learned that Romanoff only ever fell back on that when she was overwhelmed by her emotions.

The silence that settled over the comms was deafening. Romanoff's brutally honest declaration had thrown them all off balance. Up until then, they had been able to pretend that Tony was still alive. Bucky knew that was stupid — he, if anyone, knew Tony couldn't be. Even without the damning readouts from Tony's bio-monitor, the depressurization would have killed him by then.

Tony was dead.

"Barton." Steve was still clinging to his stubbornness, Bucky could tell.

"Yes, Commander?"

"How long can you give us?"

"I can launch at any time," Barton reported, "but the tilt is almost at eleven degrees."

"How long?" Steve repeated, his patience clearly run thin. Bucky swallowed, trying to catch up to what Steve was planning — he had a feeling it wouldn't be good.

"Two, three minutes, tops," Barton replied tightly.

Bucky could hear Steve take a deep breath, dreading what would come next.

"All of you, go to the MAV. Get in and prep for launch." As usual, Steve's orders left very little room for negotiation. "I'll stay here—"

"No." Panic burned through Bucky, making him reach out and grab Steve's arm. He couldn't feel much through the thick gloves and material of Steve's suit, but it was still a comfort — as if Bucky could stop Steve's foolishness simply by clinging to him.

"That is an _order_ , Dr. Barnes. Head for the—"

"Don't give me that bullshit!" Bucky snapped, his grip tightening. They were lucky he had used his right hand and not his left — his bionic prosthesis could literally break Steve's bones. "I won't let you risk your life for this!"

"I won't leave—"

"Tony's dead!" Bucky could hear his own voice waver, thick, ugly emotions making it difficult to speak. It felt like a betrayal to say those words out loud, Bucky's heart breaking from the surge of sorrow and desperation. "There's nothing we can do. We can't stay — the MAV can't take it. We'll all be stranded."

Bucky didn't want to leave Tony any more than Steve did, but they had to prioritize. He had to protect his best friend — he had to make sure Steve made it off this fucking planet alive. Tony might not be able to, but Steve still could.

The heavy silence was broken by Romanoff's softly spoken words. "Barnes is right."

Steve hesitated, clearly not prepared to give up just yet. A cold, paralyzing fear was seeping into Bucky's bones, his eyes stinging from unshed tears.

"I can't lose you too," he whispered. He knew the others could hear, but he spoke only to Steve. "Don't make me lose you too, Steve," he begged.

A second passed, then two, before Steve finally relented.

"Everyone, head for the MAV," Steve said reluctantly, defeat clear in his voice. "Proceed with the evacuation."

"Copy," Romanoff replied.

Bucky didn't dare to let go of Steve's arm — not until they were stepping into the airlock of the MAV.

They all moved efficiently and mechanically as they shed their EVA suits, falling back on years of training. The silence felt like a living entity, the lack of the usual snarky comments making it painfully obvious what they had just lost.

Who they had been forced to leave behind.

No one spoke as they climbed the ladder and strapped into the acceleration couches — no one seemed to find the words.

Bucky noticed he was shaking. He clenched his teeth, trying to blink away the burn behind his eyelids, but to no avail. His breaths trembled, catching in his throat.

This wasn't supposed to happen.

Bucky turned his head to look at Tony's empty seat, right next to his. The grief slammed into him full force, his breath hitching. He couldn't even hear Steve's order to initiate launch over the roaring in his ears.

Tony was gone.

Bucky closed his eyes, just as the first tear trickled down his cheek.

This wasn't supposed to happen.

Growing up, Bucky dreamed of becoming an astronaut with his best friend. He wasn't sure if it was he or Steve who first planted the idea, but both of them clung to it with the kind of certainty only children seemed to possess.

One day, they were going to explore space together.

It didn't take long before Bucky learned that childhood dreams weren't as easy to fulfill as he had believed when he was a little boy, but he was far too stubborn to give up. Each time a new obstacle was thrown their way, both he and Steve only seemed to become more determined. They would fulfill their dream, and they would do it together.

When both Bucky and Steve were picked for the Ares 3 crew — the third expedition sent to explore Mars — Bucky could hardly believe it. During those first couple of days after getting the news he feared that NASA would change their minds, but they never did. To reach his goal after so many years felt surreal.

He was going to Mars. He was literally living his dream.

Bucky knew that they wouldn't actually be setting foot on Mars for another couple of years — there was still training and preparations to consider, not to mention the months it would take to travel — but he was giddy with excitement.

After the accident that cost him his arm, Bucky hadn't thought NASA would ever consider him for an actual mission. Thankfully, it turned out that NASA was _dying_ to test the effects zero-g might have on a bionic limb, and Bucky was only too happy to oblige. He knew there were risks — he had to go to a total of six meetings informing him of all the ways this could go wrong — but Bucky was determined. At the end of each meeting he declared his intention to go through with the mission, no matter the cost.

He wasn't going to pass up on a trip to Mars with his best friend just because his arm might stop working.

Besides, there would be a mechanical engineer with them on the journey, in charge of maintenance and overall supervision. Bucky had met Tony Stark several times already, and while the man was both incredibly intense and arrogant to the point of obnoxiousness, it was clear that he knew what he was doing. The fact that Stark had always been on Bucky's side during the meetings — pointing out the durability and strength of the newly designed prosthetics, using technical terms that occasionally flew over Bucky's head — also helped a great deal.

That didn't mean that Bucky wasn't nervous when he was sent to have his measurements taken, to ensure that the new prosthetic fit him with NASA's usual perfectionist standards. Bucky was still a little wary whenever someone wanted to poke and prod at what little was left of his left arm.

Bucky couldn't quite hide his surprise when he stepped inside the lab and Stark was the one who greeted him. The fact that Stark was wearing a pair of tattered jeans and a dark, long-sleeved sweater pushed up to his elbows didn't help. Bucky had only ever seen Stark in crisp, tailored suits before, his hair neatly styled and grin sharp. Here, in clothes Bucky was pretty sure had at least three holes in them, Stark looked more human than he had during the meetings with the higher ups.

The change was kind of unsettling.

"Dr. Barnes, glad you could make it. Right this way." Stark gestured towards a chair placed next to one of the lab tables, his movements effortless and relaxed. The easy smile on his lips helped settle some of the tension Bucky could feel coiling inside of him.

Bucky was confused to note that they were alone in the room — things like these usually required a small team of scientists. Even so, he did as told and sat down on the unexpectedly comfortable chair.

"Anything I need to know before I get started?" Stark asked, typing something on the nearby computer. Bucky couldn't see the screen from where he was sitting. Stark shot him a wide, dazzling grin, the playful spark in his eyes making him look nothing like the brash, relentless man Bucky had seen during the meetings. "Medical history? Allergies? Music preferences? Favorite color?"

"Blue," Bucky replied automatically, feeling a little dumb.

"A traditionalist." Stark nodded, a lock of hair falling into his eyes. Bucky had to quash the impulse to reach out and brush it aside. "Do you mind if I play some music?"

Bucky shook his head before glancing around the lab. "It's just us?"

Stark shrugged nonchalantly. "You're a doctor, I'm an engineer. If we put our two clever heads together, I'm pretty sure we can make this beauty work." Stark stepped away from the computer and pulled up a chair of his own, winking at Bucky. "Besides, I designed it — no one knows how the arm works better than I do."

It was on the tip of Bucky's tongue to ask about that — Stark had never said he was the designer during the meetings — but Bucky decided that he had looked like enough of an idiot for one day.

"Works for me," he said instead, smiling crookedly. He was secretly grateful that there wouldn't be anyone else in the room with them — he felt less like a freak that way.

"Excellent." Stark took a seat and reached over to the computer to tap on a couple of keys. "Now, AC/DC or Black Sabbath?"

"Metallica," Bucky replied, grinning at the scandalized look he received.

Stark scoffed, his lips twitching towards a smile. "Fine, have it your way — but only this once." The teasing look Stark shot him, a spark of genuine warmth through long, dark lashes, sent a little jolt straight to Bucky's heart.

The music started playing over the lab speakers and, for some reason, Bucky found that he couldn't stop grinning.

Bucky saw a lot of Stark after that. Not only did they have several more sessions to work on the prosthesis, but there was mission training as well. The other four crewmembers were involved in those too, of course, but Bucky couldn't help that some fraction of his attention always lingered with Stark.

All in all, Bucky liked their crew — which was fortunate, he supposed, considering the amount of time they would be spending together.

Bucky trusted Steve with his life and had no trouble following his command. The difficult part was not slipping into fond bickering while on the comms, and not tease Steve about being a botanist about to be sent to Mars — a planet where nothing grew.

Natasha Romanoff — Russian cosmonaut, geologist, and quite possibly a spy — was as terrifying as she was competent. Bucky liked her instantly, if only because he knew that she would help keep Steve in line. She was guarded and held herself at a certain distance from the rest of them, but Bucky suspected that would pass once they earned her trust.

Their pilot, Clint Barton, was a little more difficult to pin down. He acted carefree and nonchalant most of the time, trading jibes with Stark as easily as breathing, but Bucky had a feeling there was more to him than that. There was too much intelligence in his eyes, and sometimes Bucky couldn't help wondering exactly what Barton saw when he looked at the rest of the crew.

Thor Odinsen was by far the friendliest. The Norwegian astronaut and chemist had insisted they call him by his first name rather than his last, and Bucky hadn't quite figured out if that was a cultural thing or Thor being Thor. Everything Thor did seemed so genuine, somehow, which in turn made him into one of the most dependable people Bucky had ever met. It was comforting to know that he would be along for the ride.

Stark, though, continued to be frustratingly unpredictable. There were times when he was warm and friendly — always willing to help, laughing along with the rest of them — but he could just as easily switch over to fake smiles and cutting words, often without warning. Despite his changeable personality, Stark was a genius with machines and computers, and had a work ethic that bordered on obsessive. He might be tricky to get along with, but there was nothing wrong with Stark's dedication. Bucky knew that Stark would do his absolute best to ensure that the ship, their equipment, and Bucky's arm remained functional during the entirety of the mission.

There were occasional bumps during training — which was expected when combining a group of such widely different people — but the more the crew worked together, the more confident Bucky grew of their success. Steve was a natural leader and the rest of them seemed to find their appropriate places soon enough.

Bucky had no doubt that they'd pull off this mission without a hitch.

Bucky discreetly rolled his shoulder, trying to get rid of the annoying pinch he felt. Stark noticed immediately, despite being busy running simulations on the computer.

"Are you in pain?" he asked, a small furrow between his brows. He stopped typing and looked at Bucky, who sat in his usual chair.

"Nothing I can't handle," Bucky replied as he flexed his fingers, marveling at how fluently the metal plates moved. He had no idea how Stark had been able to build a prosthetic this complex, but he felt incredibly lucky to be the one who got to wear it. He didn't even dare consider the price tag.

The small furrow developed into a full-blown frown. "Wrong answer, Barnes. Even a little pain will grow unbearable in the long run." Stark abandoned the computer and walked to stand in front of Bucky. "Where does it hurt?"

"Back of my shoulder," Bucky replied, knowing there was no point in arguing. Stark had veto on the prosthetic — if he wasn't pleased, NASA wasn't pleased, and that meant no Mars for Bucky. "It's not that bad," he added, perhaps a little more sullenly than necessary.

"I'll be the judge of that," Stark replied as he circled around Bucky's chair. There was a fleeting brush of fingertips against Bucky's flesh shoulder — the bare skin not covered by his undershirt — and he tried not to shiver. Stark was surprisingly tactile, each pat on the back and playful nudge helping him convey the concern and care he didn't seem able to verbalize.

Stark was always gentle when he touched Bucky, but he didn't treat him like he was an invalid, afraid to break him. Bucky found it comforting just how often and casually Tony touched him, as if that was nothing out of the ordinary. The certainty Stark radiated made Bucky feel like he belonged, and it was obvious that Stark didn't see Bucky as less of a person just because he happened to be missing an arm.

"It hurts when you move?" Stark asked, clever fingers running along the seam where metal met skin. The touch was distracting and far too pleasant, causing a telltale squeeze in Bucky's gut — one he did his best to ignore.

Bucky swallowed tightly. "Yeah," he replied, grateful that his voice wasn't as hoarse as he had feared.

Stark hummed noncommittally, thankfully too focused on what he was doing to notice Bucky's difficulties. Bucky knew exactly what was growing in the pit of his stomach — had been for the past three weeks — but he was determined to ignore it. Putting a name to the emotion, much less acknowledging it, was a very bad idea.

"We need to work on the angle and weight distribution," Stark said, as if Bucky would be able to offer some kind of insight in return. Mechanical engineering wasn't his strong suit.

"Do what you need to do," Bucky replied, which earned him a low chuckle.

"You have quite a lot of faith in me, Dr. Barnes." Stark nudged his arm. "Raise it for me, as high as you can."

Bucky did as told, a stab of pain making him flinch. He tried to keep going, but Stark quickly placed a hand on his bicep, halting the movement.

"I guess I should have specified 'until it hurts,'" Stark said.

"Yeah," Bucky agreed with a grimace, "that would have helped."

This time he shivered noticeably when Stark's hand slid up along his arm, stopping on his shoulder. Bucky couldn't feel the touch against the metal, but when it reached his bare skin he certainly did.

Bucky cleared his throat, fumbling for another subject. "And why wouldn't I have faith in you? I've heard you're the best engineer NASA has."

"Flattery will get you everywhere, doctor," Stark replied with what could only be described as a purr. Bucky was instantly grateful that he wasn't actually able to see Stark's face — and that Stark couldn't see his.

One of Stark's palms continued to rest on Bucky's metal shoulder, the other carefully touching along the edge of the prosthetics. "Move your arm forward, straight out in front of you. Stop if it hurts."

Again, Bucky did as told, stopping when he felt the first spike of pain.

"Good. Now let it relax again."

"I'm just sayin'," Bucky picked up, moving his arm as Stark instructed. "NASA are perfectionists, they only want the best. So you must be doing a good job."

Stark scoffed. "Well, I have to make sure to prove my old man wrong, don't I? You can't imagine how angry he got when I decided to go into robotics instead of weapons design." Stark let out a sharp, humorless chuckle. "On second thought, _everyone_ knows that, considering my current lack of billions."

The words faded and Bucky didn't know how to reply. The hand on his shoulder stiffened before pulling back, a loaded silence settling between them.

Stark had never mentioned his family before. Bucky was aware that Stark was, well, a Stark — a disowned one, but a Stark nonetheless — but that had never seemed to be something Stark felt comfortable discussing. Judging by the sudden tension in the air, Bucky's assumption was correct.

Bucky took a measured breath, praying that he wasn't about to fuck this up.

"He was wrong," he said, with as much conviction as he could muster. He didn't turn around, knowing that Stark probably didn't want to look him in the eye.

The thought of Stark having gotten disowned for pursuing what he enjoyed hit a chord within Bucky. Their situations were far from similar, but Bucky knew what it was like to fight for a dream that seemed impossible to fulfill — how difficult it was to keep going when everything seemed to be against you. Stark had his respect for following through, despite the literal fortune he had lost.

Perhaps it was the fact that they weren't facing each other — limiting the awkwardness of the situation — but Stark relaxed. He didn't say anything, but when a warm, calloused hand settled on Bucky's right shoulder, he chose to take that as a good sign. There was both care and gratitude in that gesture.

"Let's get back to work, shall we?" Stark said after a couple of seconds, his tone softer than his words might suggest. "By the time I'm done with this, you'll never want another arm again."

Bucky turned his head and looked up at Stark. Their gazes met, a second ticking by, then another. The moment held — breathless and expectant — making Bucky's skin tingle.

"I know," was all he said, not surprised by the amount of sincerity and trust those two simple words contained.

Stark remained silent, his expression unreadable, before he gave Bucky's shoulder a gentle squeeze. His smile was smaller than usual — shy, almost — but there was a tentative spark of _something_ in those dark eyes of his, and that was more than enough to leave a warm, contented feeling in Bucky's chest.

The launch of the transport shuttle that would take the crew from Earth to their ship _Hermes_ was a success. They boarded the ship — which had been waiting in orbit since the Ares 2 crew had returned from their trip to Mars — without complications and started running all the necessary diagnostics and checkups. Once they had made sure that _Hermes_ was still in working condition, Bucky found himself a window. The view took his breath away. The only thing stopping him from pressing up against the glass like an excited five-year-old was his dignity, but it was a near thing.

That five-year-old had waited a long time to get to where Bucky was now.

He heard approaching footsteps and smiled, knowing exactly who they belonged to.

"I honestly wasn't sure if we would make it," he said, still looking out at the dark reaches of space, stars twinkling in the distance.

The spaceship hummed with activity, offering a comforting background noise.

"But here we are," Steve said, stopping next to Bucky. Steve's posture was the same as always — firm and commanding — but there was a kind of softness in his eyes that revealed just how happy he was.

They had been looking forward to this moment for _years_.

Bucky let out a slow breath. "We did it, Stevie," he said, allowing the awe to shine through.

"Yeah," Steve agreed, looking at him with a wide, dorky grin. "We did."

"Any complications? Sluggishness? Weird clicks?" Stark was running his hands along Bucky's arm, as if he would be able to feel any imperfections through touch alone.

"None whatsoever," Bucky replied patiently, though he couldn't help rolling his eyes. "Just like last time."

Stark gave him an amused look. "That's quite the attitude you've brought today." His tone was fond, his fingertips still mapping out the dips and curves of Bucky's arm.

They were sitting in Stark's lab on _Hermes_ , music playing on low in the background. Despite his initial resistance, quite a few Metallica songs had found their way into Stark's playlist, and whenever one started, Bucky had to fight down a silly grin.

The banter between them was comforting — familiar after so much time spent together — as was the genuine smile on Stark's lips, and the way their knees kept bumping. And the sight of Stark's adorably messy hair, more unruly than ever after five months in space; Bucky had to fight an urge to run his fingers through it.

"You know I have to ask," Stark said, somehow both apologetic and teasing at the same time.

Bucky couldn't help wondering how he had earned the privilege to see what Stark was like behind all the fake smiles and snark. The man usually hid behind a mask so impenetrable it might as well have been a suit of armor, but with Bucky he let his guard down. He clearly liked the rest of the crew, but Stark never looked as at ease as when the two of them were alone in his lab, working on Bucky's arm.

Bucky tried to ignore the warm glow spreading in his chest.

"I want you to have the best care possible, Doc," Stark continued. He was still smiling, his gaze focused on the panel he was opening on Bucky's arm.

Bucky felt a twinge of guilt; Stark was willing to spend hours on the maintenance and Bucky repaid him by whining. Still, Bucky couldn't help feeling that if the arm hadn't broken down yet, it probably never would. The prosthesis had held up beautifully even after months of travel and prolonged exposure to zero-g.

"I just get restless, that's all," Bucky tried to explain. "We waste hours on this every week, you know? I don't really see the point."

The arm wouldn't break — Stark had seen to that.

A short silence settled over the room, more awkward than Bucky had expected.

"I'll finish up as quickly as I can, I promise," Stark replied. There was an odd note in his voice despite his cheerful smile — a stiffness in his shoulders that hadn't been there mere seconds ago. He was already reaching for his tools, not meeting Bucky's gaze.

Bucky frowned. A sickening feeling began to coil in his chest.

Truth be told, the maintenance wasn't bad at all. Twice a week Bucky got to spend at least half an hour in Stark's company, discussing whatever topic came to mind while Stark worked on his arm. Stark never seemed to have any problems dividing his attention between the maintenance and the conversation, always tossing out sharp, insightful observations — sometimes faster than Bucky could match. During those precious minutes, Bucky was the sole focus of Stark's attention — an experience as addictive as it was nerve-wracking.

More often than not, the maintenance sessions were the highlights of Bucky's week.

He spent time with all of the crewmembers, of course — he couldn't not when they were trapped on a spaceship together — but the moments he had with Stark were special, somehow. They felt real in a way Bucky couldn't quite explain, but treasured all the same.

He knew he was attracted to Stark — Bucky had finally given up on denying it — but there was a strict non-fraternization policy, as Steve had reminded them once they had made it aboard _Hermes_. Bucky knew that he could get away with certain things on account of being Steve's best friend, but this was not one of them.

So as much as he _wanted_ to reach across the space between them and pull Stark in for a kiss, Bucky knew he couldn't — at least not while they were in the middle of a mission. The infuriating part was that Stark might actually want it too, if the lingering glances and fleeting yet sizzling touches were anything to go by. Any and all advances had to wait until they got back to Earth, however, but once they did, Bucky would definitely make sure to ask.

Today, Stark wasn't quite his usual self, however. He answered Bucky's attempts to start a conversation with short, noncommittal replies, his gaze flitting away before Bucky had time to catch it. Stark wasn't usually this distracted.

"There, all done," Stark announced suddenly, scooting back.

Bucky actually flinched. "What?"

Barely ten minutes had passed — this usually took half an hour, sometimes more.

"Well, you're right that I don't need to perform a full maintenance check each time," Stark explained, putting his tools back on the table. His smile didn't reach his eyes and he quickly averted his gaze, leaving Bucky feeling off-kilter. "The arm is fine. We can cut down to one quick checkup per week, and one more thorough maintenance once a month. That should save you some time."

Bucky was desperately trying to figure out where this had gone wrong. The _last_ thing he wanted was to decrease the amount of time he got to spend with Stark. The mere thought made a cold knot of dread settle in Bucky's chest.

"But—"

"Sound good?" Stark only waited half a beat, continuing much too quickly for Bucky to give an actual reply. "Great! Now, I need to go and instruct Romanoff on _Hermes_ ' system and its maintenance, and I'm sure you have doctorly things to get back to."

Bucky's stomach dropped. He felt like the entire conversation was slipping through his fingers and he wasn't even sure why.

"No, I don't—"

"Well, I do," Stark interrupted, smiling one of those sharp, false smiles he hadn't given Bucky in over a year. It was the kind of smile that said that Stark's plans were infinitely more important than whatever objections Bucky might come up with, so he should simply stop trying.

It was the smile Stark gave people he didn't like and wanted to avoid.

"Have other things to do, that is," Stark clarified, getting to his feet. "I'll see you next week, Dr. Barnes."

Stark was already out of the lab by the time Bucky's brain caught up and his desperate, "No, wait!" got cut off by the automatic doors sliding shut.

Bucky blinked, not sure what had just happened. He knew he'd done something — he must have. Stark only started deflecting like that if he felt defensive and vulnerable, and he hadn't had a reason to act like that around Bucky for a long time. Something was wrong.

Bucky desperately thought back on what he had said, trying to figure out what had upset Stark. It didn't take him long to realize — the answer was mortifyingly obvious, even. Bucky bit back a groan, running a hand through his hair.

Did Stark honestly believe that Bucky saw their sessions together as a waste of time?

That wasn't what Bucky had meant at all, but he couldn't blame Stark for misunderstanding him. Bucky should have clarified that he loved spending time with Stark, but would prefer if they did something else than work on his arm. That's what he should have said.

Bucky gave himself a couple of seconds to regroup before he got to his feet and left the lab.

He needed to find Stark.

 

**Notes for the Chapter:**

> Come say hi on [Tumblr](http://amethystinawrites.tumblr.com/)!


	2. The Separation

 

* * *

 

Finding Stark took longer than Bucky wanted, but he was determined to set things right. Preferably before Steve got involved; Bucky was not in the mood for Steve's disappointed face. More importantly, Stark deserved an apology.

While Bucky and Stark were confined to the same spaceship — and should therefore inevitably have to meet at some point — Bucky decided that the sooner they talked, the better. That did _not_ give him the authority to interrupt Stark and Romanoff in the middle of a system check, however. Bucky had to wait until they were done and ambush Stark once he left the control room.

The slight flaw in Bucky's plan was that they'd be in zero-g, which was less than ideal if the purpose was to hold a serious conversation. Several of the rooms on _Hermes_ had artificial gravity, making it possible to stand and walk as if on Earth, but the rotating hub connecting the rooms did not. Still, Bucky couldn't risk Stark slipping past him, so he waited where he knew he'd be able to catch him.

It turned out he had to do so quite literally.

The moment Stark entered the corridor, his eyes locking with Bucky's, he had to know why Bucky was there. Despite that, Stark tried to drift past with nothing more than a curt nod.

"Stark, wait." Bucky grabbed Stark's wrist, being extra careful not to squeeze too hard — his left hand could easily crush metal, let alone fragile human bones. He found one of the handlebars with his free hand and braced his foot against a ledge, giving him enough leverage to pull Stark closer.

"As much as I would love to stay and chat, I have things to do, Dr. Barnes," Stark replied, that sharp smile of his slipping into place like a mask. Bucky felt his skin crawl.

"I—"

Stark kept going as if he hadn't even noticed Bucky trying to speak.

"Important things, I might add. So, if you don't mind..." Stark tried to unwrap Bucky's metal fingers from around his wrist, even if he had to know that he wouldn't succeed. He, if anyone, knew what Bucky's bionic arm was capable of.

Was Stark that desperate to get away from Bucky?

"Stark, please listen to me," Bucky pleaded. "I'm sorry."

Stark scoffed. "What could you possibly have to be sorry for?"

The biting tone and the way Stark avoided Bucky's gaze said that he knew exactly what Bucky was referring to.

"For the things I said. I didn't mean—"

"I have no idea what you're talking about," Stark interrupted, yanking hard enough to make Bucky let go of his hand, if only to avoid accidentally hurting him.

A flare of desperation made Bucky reach out again, metal fingers closing around Stark's t-shirt. He tugged a little harder than he intended, pulling them well into each other's personal space. They didn't collide as much as gently bump into each other, Stark's chin just shy of grazing Bucky's forehead.

When Stark reached for something to hold on to, Bucky instinctively tried to help steady him by wrapping an arm around Stark's waist. A split second too late Bucky realized he had let go of the handlebar, but, fortunately enough for them, Stark managed to grab it in his stead.

This was why holding conversations in zero-g was so difficult.

Stark didn't look happy, his jaw tightly clenched and eyes dark. His free hand rested on Bucky's shoulder, but there was no intimacy in the gesture. If anything, Stark seemed moments away from using it as leverage to push away, his posture tense and guarded.

Bucky had to admit that it felt strange to be looking _up_ at Stark, their faces inches apart. They had never been this physically close to each other before. Stark touched Bucky with regularity — which meant that Bucky had started doing the same — but this wasn't just a pat on the shoulder or a shy brush of fingers. There was almost no space between them, their legs tangling.

Had it not been for Stark's cold glare, Bucky's heart might have skipped a beat.

"What's your deal, Barnes?" Stark snapped. Despite the harshness in his voice, he made no attempt to pull away. If he did, Bucky would let go — there was a difference between ambushing someone and physically restraining them against their will. But for now he chose to hold on, until Stark showed that he wanted to put more distance between them.

"You misunderstood me." Bucky reached around Stark and grabbed another handlebar with his free hand, trying to ignore that he was practically hugging the man.

"Yeah, well, considering the mixed signals you're sending, I can hardly be blamed for that, can I?" Stark sounded angry, but the fact that he stood his ground instead of trying to run away had to be a good sign. Maybe, just maybe, he wanted to fix this too.

"No, you can't," Bucky agreed. "I didn't explain properly." He took a deep breath. "I _do_ want to cut down on the maintenance sessions—" he could feel Stark stiffening in his arms and hurried to continue, "—but not for the reasons you might think!"

"Then what?" Stark asked, his expression carefully blank.

There was a tense pause, Bucky swallowing down his nerves. He couldn't say _why_ he was so nervous — he only had to tell the truth. Then again, doing so while pressed up against the man he had been mooning over for months was a little distracting. Bucky could barely remember how to form sentences.

"I want to cut down on the maintenance, but not the time I spend with you." The words came easily after that admission. "The arm won't break — we both know that — and I just wish we wouldn't waste so much time on it."

Stark frowned. "That's what the maintenance is _for_ , Barnes. Your arm is the reason you come to those sessions in the first place."

"No, it's not." Bucky held Stark's gaze, his heart racing. His voice was softer than intended. "It's really not, Tony. Not anymore. You must know that."

Bucky couldn't remember if he had ever called him Tony before, but the name felt surprisingly comfortable on his tongue.

Stark remained quiet, his eyes a little wider than usual.

Neither of them seemed to know how to proceed. The air felt thick and heavy — too warm to breathe — and the silence rang out louder than any words could have. This was the closest either of them had gotten to addressing what was growing between them, and the look on Stark's face said that he knew exactly how dangerous this moment was.

They were balancing on an edge they should never have approached in the first place.

Stark licked his lips and Bucky felt a shiver run down his spine, but he couldn't tell if it was due to nerves or anticipation — perhaps a bit of both. Bucky's heart fluttered in his chest and he held his breath even if it made his lungs burn, mesmerized by the look in Stark's eyes. There was hesitation — thoughts of duty and regulations, no doubt — but underneath that was a fire so intense it made Bucky's head spin.

He wanted that fire. He wanted to taste it and hold it — feel it consume him.

Bucky tightened his grip around Stark's waist, pulling their bodies closer together. Stark came willingly, and even though he was still floating a couple of inches above Bucky, Stark seemed to fit perfectly in his arms — as if he belonged. Bucky could feel Stark's trembling exhale against his lips, his gut clenching from need.

He wanted this. God, did he ever. Bucky knew he shouldn't — Steve would be so disappointed in him for breaking this particular rule — but what little discipline he had left seemed to vanish when Stark's fingers wandered into his hair, combing through the short strands.

Neither of them seemed to be breathing, too caught up in the moment.

Given another couple of seconds, Bucky would have kissed Stark — probably without feeling even the slightest bit of remorse. As it was, he heard someone coming a fraction of a second before he caught the movement in the corner of his eye. He quickly turned his head, meeting Romanoff's calm gaze as she pulled herself into the corridor.

Bucky had forgotten about her. Of course she would come passing through — she and Stark had been working on the system together. A cold rush of dread washed through Bucky; it had to be obvious what she had just interrupted.

The most frightening part wasn't that they had almost gotten caught red-handed, however, but the fact that Romanoff didn't look the least bit surprised. She didn't say a word, but that was somehow more effective than any reprimands or jibes would have been.

Bucky was both disappointed and grateful when Stark pulled back, slipping out of Bucky's embrace. When Romanoff eventually drifted past, Bucky managed a tight smile. She raised an eyebrow in response, but still said nothing.

The silence was beyond uncomfortable, and neither Stark nor Bucky seemed to know how to break it once Romanoff had headed down the passageway towards the rec room. They were holding on to opposite walls, the distance between them feeling much bigger than it actually was. Stark cleared his throat and looked everywhere but at Bucky.

"Well, I should..." Stark gestured vaguely, as if he couldn't quite find the words to finish the sentence.

"Yeah," Bucky agreed, voice hoarse. "Yeah, we should probably..." Bucky trailed off, equally unsure of how to proceed.

They shouldn't have let it go so far. They both knew they couldn't act on their feelings — not yet, at least. They had to be more careful.

"We shouldn't." It took a second before Bucky even realized he had said the words out loud.

Their gazes met, Stark's sharp and calculating. After a couple of seconds Stark let out a strained chuckle, his shoulders slumping. There was both understanding and disappointment in his eyes, his smile crooked.

"Yeah, better not." He was attempting to sound amused, but Bucky heard the frustration underneath.

"I'm sorry." If Bucky could change the situation, he would.

Stark rolled his eyes. "Stop being so dramatic, Doc." His smile became more genuine, a bright spark of promise appearing in those gorgeous eyes of his. "Besides, it's only temporary."

Bucky's breath caught, but he managed a nod. So Tony wanted this too, once they were back on Earth.

"Also," Tony continued, his tone teasing, "next time you want an excuse to spend time with me, let's just watch a movie, okay?"

Bucky felt his stomach flip, hope and relief blossoming in his chest. They might not be allowed to kiss, but not even Steve could tell them they couldn't be friends. Bucky was willing to cling to whatever he could get at that point.

He grinned. "Copy that, Stark."

"I liked it better when you called me Tony," Stark said as he pulled himself in the direction of his lab. He spun lazily to look back at Bucky, his gaze full of fondness and warmth — something they couldn't explore just yet, but was proving more and more difficult to hide.

"I'll remember that," Bucky replied, knowing he had to be smiling like a dork.

Thankfully, Tony didn't seem to hold that against him.

Steve was the first to step out of the shuttle once they landed on Mars. Bucky was the second.

Intellectually, he knew it wasn't anything special. There had been two Ares missions before theirs and a total of twelve astronauts had visited the planet before his crew. But being the fourteenth human to walk on Mars wasn't any less amazing than being the first — at least not to Bucky. He was one of the lucky few to make it to Mars at all, and no one would ever take that away from him.

He could barely contain his awe as he looked out over the red, rocky landscape. There were certain similarities to some deserts on Earth, but still completely different.

Bucky was on a foreign planet.

A hand landed on his shoulder, and even if he was wearing his heavy EVA suit the force behind it made him sway. That meant it had to be either Steve or Thor, though Bucky was willing to bet on the latter.

"Come, doctor, it is time to set up the camp," Thor said, his enthusiasm evident in his voice. "There is much to be done."

Thor was right, of course. They needed to set up the Hab — their intended home during their stay on Mars — and make sure that the equipment NASA had sent years before the crew's arrival was still intact and functional.

Before Bucky had time to reply, another voice cut in — one that never failed to make his heart skip a beat.

"I bet I'll finish first." Tony's words were confident and teasing, making Bucky laugh. He wasn't entirely sure where Tony was — turning in the suit was cumbersome — but he didn't need to see him to reply.

"You're on." Bucky gave Thor a thumbs up, the reflective glass of their helmets making actual facial expressions impossible.

"Sign me up," Barton said, from where he was standing on Thor's other side.

Romanoff was walking a couple of paces ahead of them and didn't even bother to turn. "You are such children," she chastised. The words would have been insulting had Romanoff not had a hint of laughter in her voice.

Bucky still wasn't sure why she had never told Steve about what she had seen in that corridor a couple of weeks back, but he was grateful for her discretion. The meaningful looks she kept sending him whenever his gaze lingered a little too long on Tony were becoming unsettling, though.

"So you're not participating?" Tony asked. He must have known that Romanoff was too smart to fall for simple nagging, but playful banter was clearly a soft spot of hers. "It's okay, I understand. You don't want to risk losing — my brilliance _is_ quite intimidating. But I must say, had I not been here, I would definitely pick you as the most probable winner."

Romanoff let out one of her rare laughs. "Fine — you're on, Stark. But don't complain when I crush you into the Martian dust."

"You just turned this fun little bonding exercise into an opportunity for mauling and murder. Good for you, Romanoff." Tony didn't sound particularly frightened, however. "I'm beginning to regret my life decisions."

Steve's exasperated sigh echoed over the comms. "And _I'm_ beginning to have serious doubts about the success rate of this mission," he deadpanned, but Bucky knew Steve well enough to hear the humor underneath.

"Too late to turn back now, commander," he replied, grinning even though he knew Steve wouldn't see it. "We might as well make the most of it while we're here."

Steve huffed out a laugh, his tone fond. "Just get to work — all of you."

"Copy that," four astronauts and one cosmonaut chorused, in near-flawless unison.

"What's on the schedule for today?" Barton asked, balancing his chair on two legs, feet propped up on the table.

"Taking more soil samples," Steve replied as he walked past, pushing Barton's feet back down without even breaking his stride. It was only Barton's quick reflexes and Thor's steadying hand that kept the chair from tipping over. Thor didn't even bother to look up from his tablet.

Steve met Barton's glare with a disarmingly innocent smile — one that had Bucky hiding a grin behind his coffee cup. He had never understood how someone so devious could look so saint-like.

"Houston has issued a warning," Romanoff reported, drawing all eyes to her. She was sitting in front of one of the computers with her left hand wrapped around a mug of tea. The slight furrow between her brows was probably a bad sign. "There's a big sandstorm coming."

"If we're lucky, we'll be done before it reaches us," Steve replied. He joined Bucky by the small kitchen, picking out his breakfast ration.

Bucky sipped his coffee, back resting against the cabinets. He had always liked the slow mornings with the crew — seeing them gathered made him feel like a part of something special. Like he had a second family, be it a weird, slightly mismatched one.

Bucky looked up when Steve nudged him with his elbow, blinking in confusion when he was offered a fresh cup of coffee.

"Romanoff needs to be out there taking samples today," Steve said, which didn't really explain anything. His expression remained frustratingly uninformative, with a hint of encouragement — as if he was waiting for Bucky to catch on. "As soon as Stark gets up, he'll be monitoring the storm."

Had Bucky been a couple of years younger, he might have blushed. Now he simply cleared his throat and nodded, careful to avoid Steve's gaze.

"I'll go wake him," he mumbled and quickly downed what was left of his coffee. Bucky placed his empty cup on the counter before accepting the one Steve handed him, his heart hammering.

Steve knew.

Bucky shouldn't have been surprised — Steve could read him like an open book, and Bucky's attraction to Tony wasn't exactly easy to hide. They still hadn't done anything against regulations, but the tension was there as soon as they were in the same room. A part of Bucky couldn't help reveling in it — the feeling of wanting someone so badly and being wanted in return — but, at the same time, he was _aching_.

To soothe some of his longing, Bucky had started to help wake Tony in the mornings. It wasn't that Tony was a heavy sleeper — quite the opposite, really — but that he slept on odd hours that never really coincided with the rest of the crew's schedule. As a result, he had to be dragged out of bed most mornings, usually with the help of the coffee Bucky provided.

Bucky hadn't known that Steve had noticed until then.

The most surprising part, however, was that Steve hadn't told him to stop. Steve wasn't as bound by rules as one might think, but he was a very practical man and fraternization could get very ugly, very quickly — for everyone involved. Steve would never encourage something that might endanger the mission but, for some reason, he didn't try to stop this. Bucky wasn't stupid enough to think that meant Steve had given him his blessing, but at least Steve didn't seem angry with him.

Perhaps he just wanted Tony out of bed as quickly as possible, and Bucky had proven to be the safest and fastest way to achieve that.

Bucky pushed the thought aside and headed for the sleeping area. As expected, Tony lay curled up in his bunk, but Bucky suspected that he had to be at least partially awake. The Hab didn't have a whole lot of space and the conversation around the breakfast table must have filtered in by then. Whether or not that was enough to rouse Tony completely, well, that was another question entirely.

Bucky put his foot on the second rung of the bunk bed ladder and pulled himself up. That put him just above eye level with Tony, who was beginning to stir, probably due to the irresistible smell of coffee.

"Tony?"

He received a wordless grumble in reply, followed by Tony covering his face with the comforter. Bucky laughed and shifted to secure his balance, elbows braced against the mattress. Once stable, he reached out and let his free hand sink into the tousled mess of hair barely visible above the edge of the comforter.

Tony let out a pleased hum.

"I brought coffee," Bucky said, words soft and intimate. He knew they were walking a dangerous line — Steve was close enough to catch them — but Bucky couldn't help it.

They hadn't done anything incriminating the past couple of weeks — the near kiss back on _Hermes_ was as close as they had come — but that didn't mean that they had distanced themselves from each other. Quite the opposite, in fact.

Each touch and affectionately spoken word brought them closer together. Every exchange they shared was rife with breathless tension and that slow, steady burn of desire, making Bucky's head spin. The continued balancing act between friends and something more was exhausting to maintain, sure, but giving it up wasn't an option. They had to wait.

All in due time, Bucky told himself.

Tony peeked out from under the comforter, his eyes heavy-lidded and warm.

"You spoil me," he mumbled, but he sounded pleased rather than scolding.

"That I do," Bucky agreed, scratching Tony's scalp, which earned him a positively sinful moan. He should remember not to do that while he was balancing on a ladder with a hot beverage in one hand. Thankfully, he managed to remain standing.

Tony hummed, looking so relaxed and unguarded that Bucky wanted nothing more than to pull him into his arms and protect him from everything that might possibly harm him.

"I can get used to waking up to this in the mornings," Tony said.

Bucky's heart squeezed, and he wasn't entirely sure how he managed to draw his next breath.

"I know," he whispered hoarsely, fingers stroking through Tony's hair. He wanted it too — to be able to spend these quiet, comfortable moments with Tony without having to care about missions or regulations.

Bucky wanted it so badly it hurt.

With some effort, Bucky was able to step up onto the next rung and lean forward to place a chaste kiss on Tony's forehead. "Soon," he whispered, lips brushing against Tony's skin. "I promise."

Bucky could hear his own desperation — the hope and the yearning he was finding more and more difficult to suppress. He could see the same emotions reflected back at him in Tony's eyes, but both of them knew this was as close as they would get for now.

Even this was forbidden.

"Drink your coffee," Bucky urged, trying to ignore how raw his voice sounded. "Steve needs you to keep track of an approaching storm while they head out and collect soil samples."

Tony nodded, his fingers brushing against Bucky's when he accepted the offered cup. His warm, sweet smile was enough to send Bucky's heart racing, and he wouldn't have it any other way.

Tony rubbed his mouth, looking more and more anxious. He was monitoring the storm, as ordered, while Bucky and Barton worked on soil samples taken the day before. The other three were outside the Hab collecting more, Steve and Romanoff bickering fondly over the comms.

"How bad is it?" Barton asked, making Bucky jump in surprise. He had been debating asking the same thing, and the look from their pilot said that Barton had noticed and decided to take matters into his own hands.

Tony didn't even glance up from his screens. "I'm waiting for Houston to confirm, but it looks bad."

"'Abort mission' bad?" Barton frowned and straightened on his chair.

"Maybe." Tony tapped on a couple of keys before gritting his teeth, eyes flitting over the screen. He had apparently gotten a reply from Houston. "Fuck," he hissed, which meant it couldn't be good news.

Bucky felt his heart sink. They had only been on Mars for six sols out of the planned thirty — none of them wanted to abort the mission this early.

"Commander," Tony radioed, "the storm has been upgraded to 'severe.' It will be here in fifteen minutes."

There was a brief silence before Steve replied, his tone grave. "Everyone, head back inside. We'll see if we can't wait it out."

Bucky and Tony exchanged a look, but neither of them said anything. They could only wait and hope.

The storm was roaring outside, ruthlessly picking up speed for each second that passed.

Steve watched the readouts on Tony's screen while Bucky watched Steve. He knew what their commander's decision would be even before Steve voiced it out loud, simply by watching his posture.

"We're aborting." Steve didn't look happy, but if it was because they had to leave Mars ahead of schedule or because of the danger caused by the weather was difficult to tell. "Everyone, get to the MAV."

"Copy that," Tony replied, typing out a quick message to NASA, informing them of the evacuation.

The others moved to obey Steve's order, but Bucky lingered behind Tony's chair.

Bucky was disappointed that they wouldn't be staying for the full thirty sols, but he would much rather make sure that he and his crew made it back to Earth alive. His hand strayed, brushing against Tony's shoulder.

Tony looked up at him, smiling softly. "Don't look so worried, Doc," he said. "We'll be fine."

"Yeah, I know," Bucky replied. He allowed himself the forbidden pleasure of running the back of his fingers against Tony's cheek.

Tony closed his eyes, leaning into the touch. "We'll be fine," he repeated, this time with enough conviction to ease some of the tension building in Bucky's chest.

He wanted nothing more than to bend down and kiss Tony, but he knew he couldn't.

Later, Bucky told himself — he would get his chance later.

Bucky didn't even get a chance to say goodbye, much less ask for a kiss. 

The remaining crew was quiet as they boarded _Hermes_ , several weeks earlier than planned. Bucky stared at the walls, the floor — anything but the others. He didn't want to see the grief in their eyes.

He didn't want them to see the grief in his.

They did what they had to, prepping the ship for the return trip to Earth. The only words spoken were Steve's orders, his voice low and clipped, with a barely discernible tremble. Bucky thought he heard Thor sniffle, as if he was trying to stifle a sob, but didn't stay long enough to confirm it.

As soon as he was able, Bucky fled to his quarters. He could hear Steve calling his name, but he didn't care. Bucky needed to be alone. There was a silence inside his head that grew louder with each painstaking beat of his heart, pressing against his eardrums. His thoughts had come to a complete standstill, and Bucky just didn't know what to do.

He couldn't think. He could barely breathe.

The door slid shut behind him and he leaned back against it, staring at the floor.

Tony was dead. They had been forced to leave Tony behind.

A painful jolt, in the vicinity of Bucky's heart.

Bucky closed his eyes. Something was building at the back of his throat, but he couldn't tell if it was a sob or a scream. He hoped to keep it trapped behind his tightly clenched teeth. There was a taste on his tongue — sharp like blood but closer to fear — and he just couldn't swallow it down.

Tony was gone.

Bucky's knees buckled. He sank to the floor, trying desperately to suck in his next breath. Something was squeezing around his ribcage, making his head spin. Bucky realized he was shaking. There was a gaping hole somewhere inside his chest — there had to be. He wasn't sure how else he could feel so empty.

How it could hurt so much.

Bucky had always been quiet in his grief. He kept his pain to himself; he didn't throw tantrums — not even when he lost his arm. As difficult as it was, he always tried to grin and bear it rather than lash out. He didn't want to worry Steve. He didn't want to seem weak. He had been able to handle everything life had thrown at him — overcome every obstacle and faced each loss without backing down.

But not this. Not Tony.

A strangled sob was all he managed before everything came crashing down — before he shattered.

There was a burn behind his eyelids and an unbearable pain blossoming inside his chest. His breaths faltered when the loss started clawing its way up his throat. He could feel it building inside of him, pushing against his ribs, trying to break free. He felt it rip through muscle and bone on its way to the surface. He couldn't contain it.

He stopped trying.

The scream didn't even sound like his own. It was torn from him, full of anger and pain, echoing against the walls of his room. He screamed until he lost his breath. Until all he had left was that aching, overwhelming sorrow. He screamed until his voice cracked.

Bucky's back was pressed against the door, air whistling into his lungs, and he couldn't stop screaming. He barely even noticed the tears, or the hitch in his breath. He couldn't think beyond the grief — the crushing realization that he had waited too long, and lost everything because of it.

Tony was gone. Bucky would never get to kiss him or hold him or wake up next to him.

Tony was dead.

Bucky screamed until he choked, a broken sob taking its place.

He screamed until all he could do was cry.

Bucky didn't know how long it took before Steve knocked on his door — it might have been hours for all he knew.

"Bucky?" Steve's voice was raw, as if he was the one who had been screaming like a wounded animal. Or maybe it was hearing Bucky do it that made him sound that way. "Can I come in?"

A lump lodged in Bucky's throat. "No," he croaked, squeezing his eyes shut. He had curled up against the door, knees raised and forehead resting against them.

He couldn't face Steve like this. Bucky wouldn't be able to handle the sympathy he knew he'd find as soon as he looked at Steve. The pain was still too vivid, closing around his heart like cold, ruthless fingers.

There was a muffled sound on the other side of the door; Steve must have taken a seat on the floor, like Bucky.

"Okay." Steve cleared his throat, but no matter how hard he tried, Bucky still heard the grief and worry in his words. "I'll just... wait here. If you need me."

Bucky pressed his lips together, trying to force his breathing to remain stable. The silence was heavy — much heavier than it had ever been between the two of them.

"I'm so sorry, Buck." Steve sounded painfully sincere, which only made it more difficult for Bucky to maintain his fragile calm. He wanted desperately to find something to cling to — something firm that might guide him through the chaos of emotions he was experiencing. He knew Steve could help, but Bucky wasn't ready.

It still hurt too much.

Bucky drew a trembling breath, his limbs weak and unresponsive. "Me too," he whispered. "I should have..." He swallowed the rest of the words, not able to voice them out loud.

He should have ignored the stupid rules. He should have treasured what he had — while he still had it. He should have kissed Tony when he had the chance.

Steve didn't reply, no doubt caught between his duty as their commander and his duty as Bucky's best friend.

The ensuing silence allowed Bucky time to breathe. He couldn't deny that it felt marginally easier, knowing that Steve was on the other side of the door. Bucky ran a shaking hand through his hair, the exhaustion settling like a weight on his shoulders.

"If I could change what happened, I would," Steve said. Bucky heard the guilt in his voice.

"Steve, it wasn't your fault." It took so much effort to say those words. It wasn't that Bucky didn't believe them — this really wasn't Steve's fault — but it was difficult to be strong when all he wanted was to cry.

"I wish I could change it all the same," Steve replied stubbornly. "You don't deserve this. Neither did Stark."

"Tony." The name slipped out without Bucky's consent, something raw and ugly settling in his throat the moment it had. He wondered how often he would say that name from now on, and if it would ever stop hurting. His breath hitched when he tried to speak next. "He prefers— _preferred_ Tony."

Bucky let his head thump back against the door, fighting the tears threatening to fall. He felt numb — hollowed out — and wanted nothing more than for this nightmare to end. Except he knew he wasn't dreaming.

This was real, and Tony was dead.

"Should I leave?" Steve asked quietly. His tone said he didn't want to, but would if Bucky asked it of him.

Bucky shook his head, even if Steve couldn't see it. "No, it's okay." He swallowed, not even caring how wrecked he sounded. "I just... can't. Not yet."

"Then I'll wait," Steve replied, "until you're ready."

"Thanks," Bucky croaked, his throat tight with emotion.

"I'm with you, Buck, 'til the end of the line."

That was the same promise they had given each other ever since they were little kids, dreaming of becoming astronauts together. Not for the first time, Bucky found himself longing for those innocent days, when happiness came easy and everything seemed possible. The future had seemed so bright back then.

Now he wasn't even sure how to face the next couple of hours, let alone the coming days.

Bucky closed his eyes, forcing his breaths to slow despite the sorrow clawing at him. He would survive this too. He had to. The regret would no doubt make it difficult, but he had to try — for Steve, if nothing else.

He had to try.

"'Til the end of the line," he mumbled.

"We'll get through this," Steve said, voice soft.

Bucky swallowed. "Yeah, we will," he replied. "We always do."

Except deep down, he wasn't so sure.

 

**Notes for the Chapter:**

> Everyone still with me? Take a couple of deep breaths, loves.
> 
> As you might have realised, this fic is going to be entirely from Bucky's POV, so to those of you who know the source material, it's going to look a little different, yes. I wanted to explore what the story would be like from the viewpoint of one of the crew, because I figured that would be more interesting. Also more painful, but that was unintentional.
> 
> Also! Since the amazing [Shi_Toyu](http://archiveofourown.org/users/Shi_Toyu) has looked over the changes I did to the epilogue, I will now be uploading chapters twice a week, on Tuesdays and Fridays! Four more to go!


	3. The Grief

 

* * *

 

No matter where Bucky looked, there was a gap. An unused room next to Barton's. A quiet lab, once loud and bustling. Several silences in various conversations where the expected rejoinders never came.

That morning, like the one before it, was no exception. Bucky stared at the table in silence, not wanting to see the empty chair opposite him. The others were talking, but he didn't bother to listen; their conversation was white noise in his ears. He ate mechanically, barely even registering the taste.

Some holes gaped wider for each week that passed, while others were filled.

Romanoff was proficient enough at the system to serve as its operator. Barton took over as the reactor technician. Steve, Thor, and Bucky shouldered extra shifts in the bio lab.

One could almost pretend that they had always been a five-person crew. Almost — but for one thing.

No one knew what to do about Bucky's arm. No one knew how it worked or how to perform maintenance, should it become necessary.

Not that it ever did.

The arm worked beautifully — as it always had. Even without the weekly checkups it held up against anything Bucky and space could throw at it. The arm was, inarguably, a masterpiece.

Tony really had made sure that Bucky would never want — or need — another prosthetic ever again.

Bucky flinched when he felt a gentle hand on his shoulder, dragging him back to the present. He was met by Steve's worried eyes and the tense silence that had settled over the breakfast table. A careful glance from Steve made Bucky look down, only to realize that he was gripping the edge of the table hard enough to dent it.

His metal fingers whirred softly when he let go. No one said a word. Bucky took a deep breath before rising to his feet, his chair clattering to the floor. The silence was too deafening, and Bucky didn't want to risk his eyes straying to that empty spot at the table.

He stormed out of the room, heedless of Steve calling for him to wait.

Bucky didn't really talk about it. He couldn't find the words.

The others did, amazingly enough, mostly thanks to Thor and Barton. Steve might be an exceptionally good leader, but delicate emotions weren't always something he knew how to handle — especially not his own. He seemed to find it easy to talk to Thor, though, and Romanoff and Barton had always gravitated towards one another, ever since day one.

Despite what had happened, the rest of the crew was managing fairly well, in other words.

Bucky was grateful — seeing them smile again was a relief. And if the worried looks Steve threw his way only grew more and more frequent, well — Bucky could ignore that.

He wasn't ready yet.

"Hey, Stevie?" Bucky said, not looking up from the slide he was studying. His voice sounded hoarser than he remembered, but perhaps that was to be expected considering how little he had spoken the past month.

"Yeah?" There was enough hope in Steve's voice to nearly break Bucky's heart. Maybe he should make an effort to talk to Steve more often, to stop him from sounding so worried.

"Could you do me a favor?"

Steve didn't even hesitate before replying. "What do you need?"

Bucky waited a moment before looking up from his microscope, not surprised to find that Steve had abandoned his soil sample. Bucky held Steve's full attention.

"When we get back to Earth, ask Peggy for a date, okay?"

That clearly wasn't what Steve had expected.

"I'm not saying you have to marry her," Bucky continued, his gaze resting just above Steve's right shoulder. "But I know you've been meaning to ask her out." Bucky paused for a second, then cleared his throat. "I know it's scary, but trust me when I say that waiting too long hurts more. To lose it before you even had a chance to—" Bucky licked his lips, starting over. "Nothing hurts more than missing your chance. Trying is worth it. Promise me you'll ask her."

The silence hung thick in the lab, until Steve let out a slow breath — close to a sigh. "Okay. I promise." His smile was sad.

"Good." Bucky swallowed, nodding softly. "Good. Thank you."

Steve seemed to know better than to push for more, even if he might want to. It was obvious that Steve got more worried for each day that passed, wanting to know how Bucky was doing — hoping Bucky would choose to talk to him soon. His unspoken questions hovered almost accusingly between them, but Bucky refused to acknowledge them.

He didn't want to talk — not yet.

The only thing that mattered was to make sure that Steve wouldn't make the same mistakes Bucky had.

Bucky absently drummed his fingers against the table, his reading tablet lying forgotten in front of him. He had done his chores for the day, and it was becoming increasingly difficult to find ways to pass the time. There were books he could read and movies to watch, but he just couldn't seem to focus. So far, his best option was working out, but he was fairly certain that Steve was already in the gym, and Bucky didn't want to submit himself to his best friend's anxious looks.

Distantly, Bucky registered that Romanoff had entered the Rec, but he didn't offer her more than a quick glance. She and Barton were the ones who seemed the least interested in forcing him to talk, so he felt marginally more relaxed in her presence.

"Is that AC/DC?"

Bucky jumped, not having expected Romanoff to speak to him. She stood on the other side of the table, head tilted to the side.

"What?" He felt more than a little disoriented.

"AC/DC," she repeated. "'Back In Black'?" She nodded towards his hand, which had been drumming the familiar tune mere seconds earlier.

Bucky froze. He could feel stiffness settle into his spine and quickly averted his gaze.

"Yeah," he croaked, hand clenching into a fist. He could almost hear the metal creak. "I guess."

Romanoff offered him a smile before continuing towards the benches by the window, her own reading tablet ready in her hand. "You've got good taste," she called out over her shoulder.

Miraculously, Bucky kept breathing. It wasn't easy, what with the grief lodged his throat, but he managed. He swallowed thickly, staring at the tabletop.

"Thanks," he mumbled in reply.

Three months after they had left Mars behind, Bucky managed his first real smile; he knew because of the painful look of relief on Steve's face. Seeing it almost made Bucky stop smiling, but only almost.

"I hope you didn't let me win," he said instead, scraping up the winnings from that round of cards. Bucky gave Steve a teasing grin, which earned him a bark of laughter in return.

"I won't next time, that's for sure," Steve replied, tense shoulders lowering.

"Less talk, more play," Romanoff commanded, expertly cutting the deck. The fondness in her eyes and the slight smile on her lips said she really didn't mind, though.

The trip back to Earth was, in many ways, uneventful. The crew handled their appointed tasks and _Hermes_ , thankfully, needed no bigger adjustments than the occasional system update and maintenance check.

After a while, the silence got easier to handle. The gaps were still glaringly obvious and Bucky's gaze still shied away from them, but he began to relax. After four months, he felt like he could start breathing again. He still woke from nightmares about roaring sandstorms and frantically searching for something he couldn't seem to find, but it got better. It wasn't perfect, but he managed.

The messages from home helped. Each day, a data dump was sent from Houston, containing personal emails for the crew. Those were the highlight of his day, especially when his sisters wrote. If he was lucky, Rebecca sent him pictures of his niece and nephew.

As always, the crew automatically gathered on the bridge when they knew that the data dump was due. Romanoff was at her console, monitoring the download, while the others waited nearby. Barton was sprawled lazily in his seat, but the screen in front of him remained dark.

No one looked at the empty chair next to Romanoff's.

"Data dump received," Romanoff reported. "Private emails have been forwarded to your laptops, as always, and..." She fell silent, frowning at the screen.

"What?" Steve asked, stepping closer.

"There's a voice message, addressed to the whole crew." She looked over her shoulder, meeting Steve's gaze.

That was out of the ordinary, and Bucky couldn't help feeling a trickle of unease. He quickly pushed it down, just as Steve nodded for Romanoff to go ahead and play the message.

" _Hermes_ , this is Peggy Carter." The smooth British accent made Peggy's voice unmistakable. It was softer than usual, however, with a hint of weariness.

Bucky's unease only grew. There were very few reasons why the _Hermes_ flight director would contact the crew directly. The frown on Steve's face said that he was equally puzzled.

"I have some news that will no doubt be difficult to hear, and there is no easy way to say it." Peggy paused and Bucky could tell that she was steeling herself. Her voice was strong when she finally spoke, and her words shook Bucky to the core. "Tony Stark is still alive."

Steve's eyes widened in surprise.

" _What_?" Barton blurted out, but no one else seemed able to speak.

Bucky must have misheard her. Tony couldn't be alive. The depressurization and the bio-monitor—

"I know this must come as a shock to you," Peggy's continued, "and I assure you that we will answer all of your questions — in due time. For now, I will give you the basics."

"Holy _shit_ ," Barton mumbled, rubbing a hand over his mouth.

"Stark is alive and well. We found out two months ago and the decision was made not to tell you — at least not until we had established communication with him and had a rescue plan in place." Her tone was apologetic but Bucky barely registered it. His blood was roaring in his ears, drowning out most of the finer nuances of her words. "The Ares 4 crew will pick him up when they reach Mars, four years from now."

Bucky stared blankly ahead, trying to make sense of what Peggy was saying.

"What I want to stress most of all — and what Stark keeps repeating — is that none of you are to blame for what happened. We will send you a report from the incident, but it was bad luck, nothing more." There was another pause, Peggy's voice sounding softer when she continued. "This is a lot to absorb. Please take your time — your schedules for tomorrow have been cleared. If you have any questions, forward them to us and we will answer them. Carter out."

A stunned silence had settled over the bridge, echoing even louder once Peggy's message cut off. No one seemed to know what to say or do. Bucky couldn't even make sense of what he was feeling. Too many thoughts and impressions were racing through his head, clamoring for attention. He suspected he might be in shock.

It was Thor who spoke first, a wide smile spreading on his lips. "He's alive."

"Fuck." Barton laughed. "I'm not even sure why I'm surprised."

Romanoff was smiling too. "If anyone could survive that sandstorm, I guess he's the one."

"This is wonderful news!" Thor reached out and slapped Steve on the back. "Commander, we must celebrate—"

"I left him," Steve said in a monotone.

For some reason, those words were what made it hit home for Bucky. A rush of excitement and relief flowed through him, but it was almost immediately replaced by horror. The intensity of it was suffocating.

Tony was alive — and they had left him on Mars, all alone.

Bucky wanted to throw up.

" _We_ left him," Romanoff said sharply, giving Steve a reprimanding glare. He stubbornly stared back, his jaw clenched.

" _You_ were following orders. I was the one—"

"No," Bucky interrupted, voice pitched all wrong. " _I_ was the one who convinced you to leave him behind." Bucky met Steve's gaze, his stomach turning. "It's my fault."

Steve had wanted to stay. If Bucky had let him, maybe they would have found Tony. Maybe Tony wouldn't be alone on a deserted planet, struggling to stay alive.

Bucky sucked in a sharp breath, his panic building. The guilt was suffocating. "If _I_ hadn't convinced you he was dead, you never would have left."

"And then we'd all be trapped down there," Romanoff snapped.

"It wasn't your fault, Bucky," Steve cut in. Had Bucky been within reach, Steve would no doubt have placed a hand on his shoulder. As it were, Bucky was glad that Steve couldn't — he didn't deserve that kind of comfort. "I'm the commander and I made the decision to—"

"A decision _I_ forced you to make!" Bucky yelled. " _You_ wanted to stay! You _would_ have stayed, if I hadn't declared Tony dead! It's _my_ fault that he's—"

"That is enough!" Thor interrupted, loud enough to make both Bucky and Steve flinch. Thor crossed his arms over his chest, frowning at them. "This doesn't solve anything."

"I'm with Thor," Barton said as he rose from his chair. "I can tell you've got a lovely pity party going on, but this really isn't about you. Blame yourself, each other — fuck, blame God if you want — it won't make a difference. It won't change the fact that Stark is on Mars and we're not." Barton looked _disapproving_ , of all things. "What's done is done. It doesn't matter whose fault it is — that won't help Stark. So just drop it."

That was easier said than done, but Bucky chose not to say so out loud. Instead, he gritted his teeth and stared at the floor. A part of him knew that Barton was right — assigning blame really wouldn't help Tony's situation — but how could he ignore what he had done? If he hadn't forced Steve to leave, Tony might still be with them.

Steve's shoulders lowered. He didn't look particularly happy, but he seemed to be calming down. Bucky knew that the guilt was still there, though, even if Steve tried to hide it. Barton's words were well-meaning, but it took more than that to fix a situation of this magnitude.

"Let's take some time off and let it sink in." Steve looked up at Bucky, his gaze steady. "We'll figure this out."

"We will," Romanoff agreed.

Thor nodded in confirmation.

Bucky, on the other hand, chose to leave the bridge without a word.

As soon as the report from Sol 6 arrived, Bucky locked himself into his room to read it. He had spent his free day wandering the ship, trying to gather his thoughts. Unfortunately, they kept slipping through his fingers, either due to the elation of finding out that Tony was still alive, or the guilt of knowing that Bucky was the reason Tony was trapped on Mars. Bucky's mood fluctuated wildly, never quite settling for one emotion before switching to the next.

By the end of the day, he was exhausted. Houston had remained unusually silent, probably in an attempt to give them space. A part of Bucky was grateful, since that meant that he was less likely to start cursing at them for lying for two months, but another couldn't help wanting to know more, as soon as possible.

How had Tony survived? Was he doing okay? How was he going to survive on a barren planet for over four years?

One of those questions was answered by the report.

Tony had been hit by debris — a piece of an antenna — which had torn through his EVA suit and lodged in his side, damaging his bio-monitor. The final transmission saying that Tony was dead had been a malfunction, nothing more. His heart had kept beating.

He had survived the depressurization too, through sheer dumb luck. The blood from his wound had plugged up the hole in his suit, just enough for him to keep breathing.

Bucky could hardly believe it. Tony was _alive_.

As happy as that made him, the guilt was still there. Bucky knew that had he not convinced Steve to leave, they might have found Tony and been able to bring him home with them. More than anyone else, he was the reason Tony had been left behind.

Bucky couldn't forgive himself for that. He just couldn't.

It was his fault.

Now that they were in the loop, the crew received steady updates on how Tony was doing. It was both agonizing and a great relief. Tony was alive — fighting to _remain_ alive — but there was so much working against him, and no one on _Hermes_ could do a damn thing to help. They couldn't just turn around and head back to Mars — the ship wasn't built for that kind of maneuver.

Instead, Tony would have to stay on Mars until the Ares 4 crew could pick him up. That was apparently the best plan NASA could come up with, and it was certainly a lot better than Tony dying.

Bucky hadn't dared to ask Mission Control any questions aside from how Tony was handling the situation. He honestly didn't care about the scientific details — they would only make him more anxious — but he needed to know if Tony was okay.

He was doing as well as could be expected, Peggy reported. She was clearly amused when she explained that Tony had, apparently, decided to become an expert botanist overnight — thanks to the notes Steve had left behind — and started growing potatoes. On Mars.

Bucky hadn't been able to hold back a startled laugh at that, momentarily forgetting about his festering guilt.

Steve had looked both proud and a little jealous of Tony's achievements. At least until Peggy had forwarded what Tony thought of Steve's 1940's music collection — none of it flattering.

It was confusing to suddenly let go of all the grief. To find that a name Bucky hadn't dared to speak for several months was suddenly on everyone's lips. Bucky didn't mind, he just wished he could have done more — been able to help, somehow.

Perhaps that would have alleviated some of his guilt.

As it was, he could only wait and listen to reports from Houston. The plan to rescue Tony included sending him a shipment of supplies, to make sure that he actually survived until Ares 4 arrived. NASA was hard at work, building the probe, and Bucky tentatively allowed himself to hope that he'd see Tony again. It would take years, but both of them might make it back to Earth after all.

There were still risks, Bucky knew that — so many things that could go wrong, all of them capable of sealing Tony's fate. Bucky tried not to think about those, though. He didn't want to know Tony's _odds_ of survival — he just wanted him to survive.

Bucky found himself praying, more than once, for Tony to pull through. For the probe carrying the supplies to launch and reach Mars without complications. For all of this to end well, despite the numerous dangers.

It would probably take a small miracle to get Tony off Mars in one piece but, then again, if there was one person who could make that happen, it was Tony.

On the morning of the launch of the supply probe _Iris_ , no one on _Hermes_ got any work done. They all knew that Tony's survival depended on that probe reaching Mars. Without more food, he wouldn't last the four years it would take for rescue to arrive — a couple of potatoes only did so much.

The problem was that NASA didn't have the resources to build another probe, should this one fail — at least not on such short notice. Not only did it take weeks to build the spacecraft itself, but the time it took for it to travel to Mars had to be taken into account. _Iris_ had to reach the planet before Tony ran out of food — on Sol 584, according to Peggy — and that window was closing quickly.

_Iris_ was Tony's only chance.

The crew gathered on the bridge, hovering around Romanoff's station, waiting anxiously for news. Romanoff herself seemed admirably calm, but Bucky could tell it was an act. Her jaw was clenched tight and more than once he saw her hands tremble.

By the time Houston radioed _Hermes_ , none of the crew were able to hide their worry. What they received was only two simple words, but they were more than enough.

"Launch failed."

Barton cursed and kicked the base of Romanoff's chair, while Thor closed his eyes with a heavy sigh.

Bucky was busy trying to remember how to breathe.

How could this be happening? Hadn't Tony been through enough? Had he survived the sandstorm, only to die from starvation?

It wasn't fair. It just wasn't fair.

Everything from the past couple of months came rushing to the surface — the grief, the guilt, the worry, and the _anger_. Bucky had tried his best to suppress it, to keep it at a manageable level, but it was just too much. He couldn't hold it at bay anymore.

"For fuck's sake!" he growled. "What did Tony do to deserve this? Why can't NASA do their _stupid fucking job and just_ —"

"Hey." Steve held up his hands. "Calm down, Bucky."

"I don't want to calm down!" Bucky snapped back, pointing at Romanoff's screen. "That probe was Tony's only chance to survive! What are they gonna do now, huh? Just watch him die? Are we..." Bucky's voice wobbled, but he clung desperately to his anger. "Are we gonna have to watch him die? Again?"

"No, they'll think of something," Steve soothed. "They always do."

"But how long will that take them?" Bucky demanded. "Will they do it in time to save him?"

"They'll do their best—"

"That's not good enough!" Bucky roared as he slammed his fist down onto the headrest of the nearest chair. The groan of metal and splintering of plastic made Bucky realize he had used his left hand. When he unfurled it, his hand was fine — there was barely even a scratch on the metal — but the same could not be said for the chair. He stared down at the now disfigured headrest, a cold wave of shame rushing through him.

He shouldn't have done that. Bucky didn't want to be the kind of person who broke and threw things when he got angry.

He swallowed, looking up at Steve, who seemed just as startled as Bucky.

Barton was the one to break the silence, arms crossed over his chest and tone suspiciously light. "Well, at least it was his own chair he broke."

Steve shot him a withering look. "Not helping, Barton," he said, before pointing towards the door. "You three, get to work. Now."

"Copy that, Commander," Romanoff replied, rising from her chair and grabbing Barton's arm in one smooth movement, pulling him off the bridge. Thor followed without complaint.

Steve turned to Bucky, who automatically looked away, too ashamed to meet Steve's gaze.

"I didn't— I didn't mean to."

"I know you didn't." Steve stepped closer, placing a gentle, grounding hand on Bucky's shoulder.

"I'm just... I'm just so tired," Bucky whispered. "I don't know how to... handle all this." He swallowed down the lump growing in his throat. He didn't want to cry, so he forced a faint smile instead, looking up at Steve. "They never really covered this in training." It was a poor attempt at humor, but Bucky preferred that over tears.

Steve smiled back, but he looked more pained than happy. "They sure didn't."

Bucky licked his lips, glancing at the chair he had just broken. "You think NASA will make me pay for that?"

"You can't afford it," Steve quipped. There was a sudden spark of mischief in his eyes. "Tell them you were testing the strength of the bionic arm or something."

Bucky had to laugh at that, even if it was shrill and not quite right. "Oh, Tony would love that," he mumbled.

Steve smiled before pulling him in for a hug. Bucky returned it, glad to have Steve's comforting presence to lean against.

"They'll figure something out, Buck," Steve said, voice low. "They won't give up."

With some effort, Bucky was able to nod. And if his next breath morphed into a half-choked sob, well, Steve was the only other one there to hear it.

_Hi there, Doc._

_The psychiatrist NASA sicced on me says I need to write a letter to each member of the crew in an effort to "ground myself in humanity." What she really means, I think, is that we all know I might die in a not-too-distant future, but they would prefer it if I didn't lose my shit prematurely. NASA might have Pepper Potts in their PR department, but not even she can spin "mental breakdown" into something positive, and she is a master at handling the press._

_But I digress._

_I honestly don't know where to begin._

_I miss you. How about that? That's a good place to start, right? Except I suspect it will only make you feel worse, guilt-wise. Yeah, a little bird (well, he's more of a bald eagle, isn't he?) told me you've been wallowing. Don't be mad at him for ratting you out — he means well._

_It's not your fault, Doc. You made the right call — so did Rogers. You thought I was dead._ I _thought I was dead. There's literally nothing you could have done — not without jeopardizing the whole crew. Let me be the tragic, self-sacrificing hero this time, okay? It's not my usual gig, but I've always loved a challenge._

_I guess I should say something deep and moving about my courage and determination to get myself off of this big, red rock, but that's not really me. Well, I'm a narcissist and a genius and I am fully convinced that I_ will _make it off of this big, red rock, but I don't think a speech is what you want to hear. So I'll simply say this: I haven't given up yet. To be entirely honest, I don't think it's in my nature. So you can rest easy at night, knowing that I have every intention of making it back to Earth. You still owe me a kiss._

_Which reminds me: I forgot to ask if these emails were going to be screened before being forwarded to you, so I might just have accidentally outed you to NASA. Sorry. Why didn't I erase it and start over, you ask? Because I'm selfish (narcissist, remember?) and getting reprimanded for flirting with a fellow crewmate isn't even in the top ten on my list of problems right now. If I die, this won't matter anyway. If I don't, well, what are they going to do? Ban me from ever going out into space again? I'm pretty sure I'll have had my fill once this whole ordeal is over._

_Hopefully, you'll forgive me._

_I miss you. I know I said that already, but it bears repeating. I also miss coffee. I've almost run out. I'm better at rationing my food than my coffee. What I think I miss the most is you and coffee together — that will always be a favorite combination of mine. I hope you won't feel too objectified when I say that I also miss your arm. I get to build things here on Mars too, but nothing as interesting as you arm._

_As you might have noticed, writing things like this isn't my strong suit. I usually dictate all my emails to JARVIS — you didn't get a chance to meet him back on Earth, so remind me to introduce you — and he translates and/or censors them into something more palatable to the general public. No such luck here. I really hope you didn't expect something deep and profound. That's definitely not my thing. Yours is the final email, though. I saved you for last. (Is it just me or did that sound extremely creepy? It did, didn't it?)_

_The point of this long-winded email is pretty simple in the end. I'm still here. I'm still fighting. I'm a little frustrated, I can admit, and the lack of supplies heading my way is a bit of a problem, but I'll think of something. I always do. And if I can't, the people at NASA will. We'll fix this, I promise._

_So don't lose hope. And don't blame yourself — it's not your fault._

_I'll see you soon.  
Tony_

Bucky sat staring at his laptop, Tony's words tumbling around inside his head. The email was staring back at him, a gathering of small pixelated letters on his screen.

He took a deep breath and ran both hands through his hair, closing his eyes against the onslaught of emotions. He still felt guilty — he couldn't help it — and hearing from Tony only made his mistakes seem more real. If it hadn't been for Bucky, Tony might never have been left behind on Mars. He wouldn't have had to write that email in the first place.

It was true that there was no use wallowing, however. That wouldn't help anyone.

Bucky's hands fell back down, landing in his lap. Tony obviously didn't blame him. It would take a while for Bucky to process that — even longer for him to believe it.

The ship hummed around him, the noise familiar and soothing. Bucky kept staring at the laptop screen. To hear from Tony — actual words written by him and not just reports from Mission Control — felt surreal. It made the longing burst to life again, rushing through him until he was practically vibrating with need.

He didn't care that Tony might have outed him in front of NASA. Bucky would tell the whole galaxy if he thought it might make a difference — as long as he found Tony somewhere on the other end of this nightmare. That was all that mattered.

Bucky sighed and closed his eyes, allowing the tension to bleed out of his shoulders. He'd have to put his faith in Tony and NASA. There was nothing else he could do.

No one could deny that what they really needed, however, was a miracle.

" _Hermes_ , I have good news," Peggy's recorded voice said to the crew gathered around Romanoff's console.

"Well, we certainly need some," Barton muttered, even though Peggy obviously couldn't hear him.

Steve held up a hand to quiet any further comments as Peggy's voice continued to filter in over the speakers.

"Thanks to the China National Space Administration, we get a second chance at sending supplies to Mars." Peggy let out a short breath, smile evident in her voice. "They can provide us with the boosters we lack, and together we can send a second probe, which will reach Mars on Sol 624."

Bucky frowned, glancing at Steve. "That's still too late. They said Tony only had food to last him until Sol 584. He'll starve for several weeks."

Steve didn't reply, but the way his jaw tightened said he'd reached the same conclusion — and didn't like it one bit.

"The solution isn't ideal, but it's a chance," Peggy continued. "The _Taiyang Shen_ will launch in twenty-eight days. As you all know, your journey will also reach its end within a month's time, so focus on getting home safely, _Hermes_." Something soft and gentle sneaked into her voice, and Bucky didn't miss the way Steve seemed to cling to her every word. "I look forward to your return."

That was definitely intended for one crewmember in particular — her tone was unmistakable.

After a brief pause Peggy seemed to realize what she had said and hurried to amend, "We, I mean. We at Mission Control." She cleared her throat, sounding a little bit embarrassed. "Yes. Safe travels, _Hermes_. Carter out."

Bucky smirked and gave Steve a meaningful look, not surprised in the least when Steve suddenly appeared _very_ interested in the controls of Romanoff's computer. That didn't hide the telltale blush on Steve's cheeks, however.

"Oh, the curse of an Irish complexion," Bucky mumbled, quickly dodging the smack Steve aimed at the back of his head.

Romanoff rolled her eyes and muttered something under her breath, but Bucky didn't try to figure out what she had said — mostly because it was in Russian.

"So I guess this means Ares 4 can save Stark after all." Barton looked thoughtful, despite the fact that it was meant to be good news.

Then again, even if this probe launched without a hitch, Tony would have to ration his food until he could barely make it through the day. As far as solutions went, it was a desperate one, but at least he had a chance.

"It seems like it," Steve replied. "They have the best minds at NASA working on this. With the limitations they're facing, this is the best plan they have. The _only_ plan."  
  
"Well, better hope it's the plan that saves him, then," Barton said, before turning to leave the bridge.

"His optimism is astounding," Bucky said drily, but he couldn't help feeling that Barton had a point. They couldn't afford any more failures, and Bucky hoped to God that NASA knew what they were doing. This was a solution, but forcing Tony to starve proved just how desperate they were getting.

They were running out of time.

 

**Notes for the Chapter:**

> We're getting there, slowly but surely! I hope you're enjoying the ride <3


	4. The Mutiny

 

* * *

 

A sharp knock made Bucky look up, finding Romanoff standing in his open doorway.

"Come on," she said. "The commander wants to see us in the Rec."

Bucky frowned but got to his feet, following her out of his room. "Why?"

It was too late for any mission updates from Houston and Steve had always tried to let them have their personal time, so whatever it was, it had to be big.

"He didn't say." Romanoff gave him a glance that Bucky could only describe as _mysterious_. "But I think it has to do with a file Thor received with today's data dump."

That offered more questions than answers. On top of being their chemist, Thor was also their navigator and astrophysicist, but Bucky couldn't see how that might warrant unscheduled meetings late at night.

"Huh," was the only thing Bucky could think of replying, and they spent the rest of the way in companionable silence.

The other three crewmembers were waiting when Bucky and Romanoff entered the rec room. Steve stood with his arms crossed over his chest and his jaw tightly clenched. It wasn't anger — Bucky could see that right away — but something closer to apprehension. That was not an emotion he was used to seeing in Steve. The determination in his gaze, though, that was familiar.

Something was definitely wrong.

"Thanks for coming." Steve gestured towards the table where Thor was seated. Barton was sprawled on one of the benches over by the window, looking completely at ease despite the tension in the room.

Romanoff pulled out a chair, but Bucky chose to remain standing.

"What's up?" he asked.

"Mutiny," Steve replied.

"Okay." Barton sat up straighter. "That was not what I had expected, but I'm liking it so far."

"Mutiny against who?" Bucky asked.

"NASA." Thor was the one who replied, his hands laced together on the tabletop. "A file was sent to me, anonymously, containing what they called the 'Peter Parker Maneuver.'"

"Never heard of it," Barton said, looking almost frighteningly attentive despite his flippant words.

"It's a set of instructions," Thor explained, "on how _Hermes_ can use the gravitational pull of the Earth to change its course. A 180 degree change."

"So, a U-turn around Earth," Barton clarified, his eyes glowing with excitement. "Then head back the way we came."

"Back towards Mars, yes," Thor confirmed.

"You mean—?" Bucky wasn't even able to finish the sentence, unsure if he was only hearing what he wanted to hear.

_Hermes_ wasn't capable of such a sharp turn on its own — the ship was too big and cumbersome — which was why they had never been able to even consider going back for Tony themselves. But if this maneuver made it possible? Bucky would do it in a heartbeat.

"We'd die," Romanoff deadpanned. All eyes turned to her and she shrugged. "Just figured someone had to say it. We don't have enough supplies to last us another trip to and from Mars."

"That's where the mutiny comes in." Steve looked at them, one at a time, while he continued to explain. "According to the maneuver, the Chinese probe _Taiyang Shen_ could be used to send us supplies. It would only have to travel out of Earth's atmosphere, and we'll pick up as we pass."

"Like a drive-through meal but with a spaceship. This just keeps getting better and better."

Everyone tactfully ignored Barton's input.

"We would arrive on Sol 549, long before Stark runs out of food." Steve paused for a second, letting the words sink in. "The problem is that it would add over five hundred days to our mission, not to mention that if we miss that supply probe, we'll starve. And there's no telling if _Hermes_ will be able to withstand the—"

"Are you seriously trying to talk us out of it?" Bucky questioned, feeling a stir of anger. "This is the solution! This is a way to save Tony without him having to starve himself half to death!"

"I know," Steve replied, his tone sharp enough to make Bucky close his mouth with a clack. "The problem is, we're not even supposed to know about this maneuver."

"It was sent to me because I am the navigator," Thor picked up, "but it did not come from Mission Control. It was hidden and encrypted."

"What? But... that means..." Bucky swallowed.

"NASA has decided against it," Steve confirmed. "I assume it's because of the _Taiyang Shen_. They want to use the probe to send supplies directly to Mars, but this maneuver _also_ requires the _Taiyang Shen_. They can't do both — they have to choose."

Bucky gritted his teeth. "Well, they picked the wrong one."

"That's what we're here to decide," Steve said. "We can force their hand. Whoever sent Thor that file apparently didn't agree with NASA's decision and wants to give _us_ the final say."

Thor nodded. "If we choose to perform this maneuver, NASA will have to use the _Taiyang Shen_ to send us supplies. We will give them no choice."

"You want us to _blackmail_ NASA? Are you insane?" Romanoff asked, but the look in her eyes said she was already looking forward to it. She was actually kind of terrifying.

"I'm not saying anything." Steve held up his hands. "When it comes to this decision, we all have to be on board. NASA probably didn't tell us because it involves risking six lives instead of one, and I'm not going to force any of you to do that. We'll do this only if all of us agree."

Bucky opened his mouth to reply, but Barton cut in first.

"Sign me up." Barton scoffed at the angry look Bucky shot him. "Oh please. Everyone already knows you're going to say yes, Barnes."

Romanoff spoke up before Bucky had a chance to snarl something insulting. "It's dangerous, but I'm in. Our ship can get there faster than the probe."

"I want to remind everyone that this is mutiny we're planning here," Steve said gravely. "There will be consequences when we get back to Earth."

"Consequences I am more than willing to face, if it helps save a friend," Thor said, in that disarmingly sincere way of his.

Bucky's heart was racing. For the first time in months it felt like he had _hope_ — like they could actually _do_ something instead of just sitting around waiting for news from Houston.

"Bucky?" Steve urged.

"What? Yes. Of course." Bucky scowled. "Do you even have to ask?"

"I do." Steve looked at the crew. "And since I don't want any of you to feel pressured, you will get twenty-four hours to think this over and change your vote, should you want to. This is not a decision you should make lightly."

Bucky might have protested, had he not known that Steve was right. As desperate as he was to save Tony, Bucky wouldn't feel better if he forced someone else to risk their life in the process — certainly not against their will. That wasn't for him to decide.

"If we're still in agreement after those twenty-four hours are up," Steve continued, "we will head back to Mars and rescue Stark ourselves."

"About damn time," Barton replied with a grin.

He might as well have been speaking for the entire crew — Bucky saw it in their eyes. They finally had a way to save Tony, and Bucky doubted that any of them were going to say no to that. There were risks, yes, but it would be worth it.

They could save Tony.

Unsurprisingly, no one changed their minds. 

_Doc, I don't say this lightly, but what the actual fuck?_

 _You're coming to get me? Have the five of you_ gone collectively insane? _I mean, I get you and Commander Rogers — patriotism, loyalty, and foolhardy bravery are probably hardwired into your DNA — but Romanoff? She should know better!_

_I'm not saying that I'm not happy — this way I don't have to starve nearly as much as I was preparing myself for — but you might get yourself killed! If you haven't noticed, your engineer isn't on board to help you should_ Hermes _malfunction. And they call_ me _reckless._

_Speaking of which, you can't imagine the amount of nagging I had to do before Peggy let me send this to you. I don't think NASA appreciated my inefficiency last time so they put a 250 word limit, which I think is pretty rude. It hinders my creative process. Or maybe they didn't like me using their official channels to break their non-fraternization policy?_

_You know, on second thought, I should probably be happy I got to send anything at all._

_And yes, I am well aware that I'm wasting my precious words here. That's what happens when you leave a man alone on Mars for too long. I never thought I'd miss hearing other people's voices as much as I do. Luckily, it turns out I really will be seeing you soon. You have no idea how much I look forward to that._

_Please don't die before you get here._

_Tony_

"Explain why you're doing this again?" Rebecca said, frowning at the webcam.

Bucky held back a sigh. "Because it's the fastest way to rescue him."

"No, I get that bit — I _have_ been watching the news, thank you very much — what I want to know is why you're so determined to follow through."

Bucky was beginning to regret having agreed to talk to his little sister. _Hermes_ was close enough to Earth that video calls were possible, but this was reminding him more and more of an interrogation, not catching up with a supposedly loving relative.

"Because he would do the same for us," Bucky replied patiently. He was floating in his quarters, which made the conversation slightly more awkward than it usually would have been.

There wasn't much to do about that, however, since they would be docking with the _Taiyang Shen_ in a couple of days. In order to do that, they had to shut down the centripetal gravity — not even Barton was a skilled enough pilot to catch a probe if their ship was busy spinning.

"So you blackmailed NASA and voluntarily agreed to five hundred more days in space, just to feel noble?" The look on Rebecca's face said she didn't believe that one bit. She was fishing for something. "That Stark guy has to be pretty amazing." The pointed way she looked at Bucky was a dead giveaway.

He rolled his eyes, trying to hold back a smile. "Well, he does have a _fantastic_ ass."

Rebecca barked out a laugh. "Now that's more like it."

"How did you know?" Bucky asked. "Did Steve tell you?"

"About your little crush?" Rebecca shook her head. "That's all on you. You call him Tony while everyone else says Stark."

"That doesn't prove anything," Bucky pointed out.

Rebecca gave him a flat look. "You also make goo-goo eyes as soon as you mention his name. Like, your eyes twinkle. It's disturbing. You should stop."

"Har-fucking-har," Bucky deadpanned.

"No, I'm serious. You should probably have that checked out because I'm pretty sure you've reached a point where it's considered a health problem."

"She says to the doctor," Bucky replied drily. "How come I'm not safe from you even while in outer space?"

"Don't ruin my fun," Rebecca chastised. "You'll be gone for another year and a half — let me get this out of my system."

The words were lighthearted but Bucky knew there was a lot of fear hiding behind them. He felt a stab of guilt. He didn't want his family to worry, but if Bucky and his crew were able to save Tony, surely it would be worth it.

"I'll be fine, I promise," he said soothingly.

"Except they said on the news that if you miss this probe you're docking with, all of you will starve to death." Rebecca said the words without infliction, which only helped to prove just how disturbed she was by them.

"That won't happen," Bucky assured her, though he couldn't exactly blame her for being anxious.

There _was_ a small risk that Barton wouldn't be able to dock with the probe, but if that was the case, they could still grab it manually. Since he was the EVA expert, that would be Bucky's job. He chose not to mention that to Rebecca, however, since he had a feeling she wouldn't appreciate knowing that her brother might be stepping out of a moving spaceship.

"It could," she argued.

"It won't."

"It cou—"

"What are you, five?" Bucky interrupted, trying not to grin. "Seriously, Becca — we'll be fine. You don't have to worry."

"I still do, you know that." Her gaze was somber. "Just be careful, okay?"

"As careful as I can be in a spaceship fuelled by a nuclear reactor," he promised.

"Was that really necessary?" She gave him an exasperated glare, but her lips were twitching towards a smile.

Bucky grinned. "Say hello to the kids, okay? And Julie and Hannah. And—"

"I'll say hello to everyone!" Rebecca interrupted. "You just worry about getting back in one piece, okay?"

"I will." He nodded, discreetly trying to memorize the details of Rebecca's face. He couldn't say that he didn't miss his family, and with another five hundred days in space ahead of him, he felt he had the right to be a little sentimental.

"Oh! One more thing!" Rebecca's expectant grin was unsettling. "You and your crew have taken command of that spaceship of yours, right?"

"Yes," Bucky replied hesitantly, not sure where Rebecca was going with that particular line of inquiry.

"Against NASA's wishes and expressed orders?"

He nodded.

"So the five of you basically organized a mutiny?" Rebecca leaned closer to the webcam.

Bucky was beginning to feel like he was being accused of something, though he didn't know what. "Yeah, so? What are you going to do about it? Tell mom?"

"What? No, don't be silly." Rebecca waved the comment away, looking positively _devious_. "I just want to clear something up. You're telling me that you and your fellow crewmates _commandeered_ a spaceship?"

"Yeah, I guess we did." Bucky frowned. "What's your point? Why are you smiling like that?"

"Oh, come on. Can you blame me?" she replied, grinning from ear to ear. "It's not every day you find out that your brother is a space pirate."

Hilariously enough, Rebecca wasn't that far off.

Before Thor had set their new course, Romanoff had disabled the remote override to stop Mission Control from being able to steer _Hermes_ from Earth. The crew _had_ commandeered the ship — NASA no longer had any direct power over it — and could, theoretically, go off to pillage and plunder across the galaxy if they so wished. Bucky had a feeling Houston wouldn't like that, though.

Besides, they had a far more important goal ahead of them.

The docking with the _Taiyang Shen_ went as planned, without Bucky having to step outside the safety of _Hermes_ ' walls. Once the supplies had been unloaded and stored, all that was left was to wait for them to reach Mars again — which would take a while. There were a lot of preparations to be made, of course, but the crew on _Hermes_ were responsible for very little of it. Tony would do most of the work.

_Hermes_ might be one of NASA's greatest achievements, but there were certain limitations. It could orbit a planet once close enough to its gravity, but it never ceased moving. It wouldn't now either, and that meant that Tony would, in simple terms, have to get on board as they passed by the planet.

A flyby, as Barton had called it.

For this, Tony needed some kind of shuttle, except Bucky and the others had taken the MAV when they evacuated. Theirs were not the only MAV on Mars, however. Each Ares mission was planned years in advance, supplies being sent long before the crew arrived. The Ares 4 MAV was already in place, and as long as Tony could get to it, that shuttle could take him to _Hermes_.

That was apparently easier said than done, however. There was a lot of ground to cover between the Ares 3 site and the Ares 4 MAV. Tony would have to travel that distance with whatever means he had on hand — the mission Rovers, Bucky assumed — and somehow find a way to stay alive without the Hab. It wasn't just the terrain that would be difficult, but the fact that Tony would have to bring air, water, food, and some kind of energy source.

Bucky's head started spinning just _hearing_ about it.

Fortunately, Tony was the engineer, not Bucky — and a brilliant one at that. Bucky had no doubt that Tony and NASA would figure everything out.

Besides, there were other things for Bucky to worry about.

He had been informed that due to modifications that Tony would have to do to the MAV, it wouldn't be able to dock with _Hermes_. The modifications were necessary in order to conserve fuel — that was something NASA _hadn't_ been able to send an abundance of, so many years in advance — but it left the shuttle without many of its functions. That meant that Bucky would have to get out there and grab it, while both shuttle and spaceship were moving.

In theory, that sounded tricky. In practice, it would be an outright nightmare.

The two spacecrafts would not only have to be relatively close to each other, but also travel at a reasonably similar speed. Bucky only had a certain reach if he was to remain tethered to _Hermes_ , and the timing would have to be near perfect. Even with Barton remotely piloting the MAV, it was going to be difficult.

Bucky had brought up the possibility of doing the catch untethered since that would increase his range, but Steve had shut that down immediately, saying the risk was too great. He had argued that without something to anchor him to the ship, Bucky might float off course. Considering that he would have an MMU to help him along, Bucky didn't think that was very likely, but convincing Steve of that was virtually impossible. To be honest, Bucky was more worried about missing the catch than what might happen to him.

Saying so had only made Steve more determined not to let him out there without a tether.

For the most part, the crew on Hermes didn't have much to do except continue to work on the research samples they'd taken from Mars and prepare for the rescue mission. They had a long trip ahead of them — made longer by the sheer number of days they had already spent on _Hermes_ , but no one complained.

Bucky was grateful that they'd be the ones to rescue Tony, and he suspected that he wasn't the only one who felt that way. The crew had left Tony behind, and it was their job to save him. They wouldn't let him down a second time.

They would bring Tony home.

Bucky sat on the bench by the rec room window, staring out at the stars. The hum of the spaceship was a distant background noise, his thoughts blissfully quiet. He should be sleeping, but couldn't quite bring himself to move. It was soothing to sit there, knees pulled up and back resting against the wall, gazing out at space.

Footsteps alerted him of Steve's arrival, but Bucky didn't turn his head to look at him. Steve remained silent as he came over and sat down at the other end of the bench, his knee bumping against Bucky's foot when he turned to look out the window.

"This wasn't quite what we had expected, was it?" Steve asked, voice low in the quiet room.

Bucky took a slow breath before shaking his head. "Not really."

They had dreamed of space — how beautiful and amazing it would be to experience it firsthand — but it was difficult to remember that joy and enthusiasm now. More than anything, Bucky felt apprehension and worry.

This wasn't what he had pictured when he and Steve had been picked for the Ares 3 mission.

"You haven't written to him, have you?"

Bucky looked up at Steve's question, frowning softly.

Steve was smiling, though there was a hint of sadness to it. "You could, you know. Peggy wanted me to remind you of that. Stark..." Steve leaned forward, bracing his elbows against his knees. "Tony needs all the encouragement he can get."

Bucky swallowed, pushing down the surge of excitement. He _desperately_ wanted to write Tony, but he wasn't sure what to say. He wasn't sure if he would be able to keep the guilt from spilling over.

"He'd love to hear from you," Steve continued, kind and sincere.

"I know that," Bucky replied, sharper than intended. He closed his eyes, leaning his head against the wall behind him. "I just... what would I say?"

"Whatever you want."

A crooked smile spread on Bucky's lips. "What about the non-fraternization policy?" he asked, opening one eye to look at Steve.

"I'm pretty sure that ship has sailed already," Steve replied with a laugh, scratching the back of his neck. "For, uh, several of us."

"Peggy said yes?" Bucky guessed, not bothering to hold back his grin.

Steve nodded, looking adorably bashful.

"I thought you were going to wait until we got back to Earth," Bucky said, but he couldn't say that he was displeased.

"Yeah, well." Steve shrugged. "I figured I needed something to look forward to, now that we've increased the number of days we're spending in space." He cleared his throat, gaze resting on his hands. "We're gonna go dancing."

Bucky let out a fond snort. "Of course you are."

There was a short, comfortable silence; Bucky reveled in the simple pleasure of being in Steve's presence. There were few things that could make him feel so at ease.

"You should write to him," Steve said.

Bucky took a deep breath, gaze turning back towards the stars. The longing was still there — a warm, tight knot inside his chest, impossible to ignore. Guilt had made him hesitant to reply to Tony's emails, not knowing what to say, but remaining silent would probably be worse. Tony would no doubt interpret that as something bad.

Bucky smiled. "Yeah," he mumbled, "I think I will."

_Tony,_

_I'm sorry for the silence. It's not that I didn't want to write to you, I just didn't know what to say. I still don't. I keep trying to find the right words, but I'm beginning to realize I never will. There are just so many things I want to say to you._

_First of all, I'm sorry. I know you said it's not my fault, but please let me apologize for the role I played in all this. I shouldn't have forced Steve to stop looking for you so soon — we might have found you if I hadn't. I am so, so sorry._

_Second, I miss you too. I try my best not to think about it because I think the longing would eventually drive me insane. You have no idea how much I miss you, Tony._

_Third, I regret that I didn't kiss you. During the months I thought you were dead, I was so angry with myself for having missed my chance. I promise you that I won't make the same mistake again._

_Fourth, I know you think it's dangerous for us to come back for you, but you would have done the same for any of us. We don't leave crewmembers behind and we are willing to face the risks if it means bringing you home. You're worth it, Tony — ten times over. Never doubt that._

_I can't even imagine what it's like, being stuck on a foreign planet all alone, but we'll be there soon. We're coming to get you. So hold on until then, okay? We're going to bring you back home._

_There is so much more I would like to say, but I don't know how. I really don't know how to put everything I'm feeling and thinking into words. So just know that I miss you and that the crew and I will do whatever it takes to get you safely back to_ Hermes _. Maybe then I'll know what to say, but if not, there's still that kiss I owe you._

_Stay safe,  
Bucky_

The months seemed to drag on, even worse than when they had been on course for Mars the first time. Back then, it had been excitement and curiosity that drove them — a sense of adventure and purpose — but this time it was urgency. Their determination was tainted by impatience, and there were times when the strain showed.

Thor grew a little quieter, Romanoff grew a little sharper, and Barton obsessively ran simulation after simulation to prepare for the pick-up. Steve spent an unusual amount of time staring thoughtfully at nothing in particular, and not even Bucky could tell what was going on inside his head.

And Bucky, well — he had his guilt and the catch to worry about.

He knew he should have let go of the guilt long ago — even Tony told him so — but that was easier said than done. Had it not been for Bucky, none of this might have been necessary. He hadn't _meant_ for something like this to happen, but his words were what had caused it nonetheless. There was no hiding from that.

The weeks passed uneventfully, save for smaller maintenance issues with _Hermes_ and their regularly scheduled science experiments. _Hermes_ was beginning to show some wear and tear, but the crew did what they could to fix the ship, or at least prevent further problems.

Some things couldn't be helped, however, like when an unknown malfunction caused the temperature to rise uncomfortably high in Barton's quarters, which required him to move in with Romanoff. Steve was the one who suggested the solution but, judging by the looks on Barton and Romanoff's faces, they knew all about sharing a bed already.

Bucky really should have seen that one coming.

He felt strangely satisfied knowing that he and Tony weren't the only ones going against NASA's policies — not even Steve had the right to complain considering his plans with Peggy. Besides, _Hermes_ and its crew were already way outside of the usual mission boundaries, and some fraternization seemed like a small transgression compared to a full-blown mutiny.

There were other things that were more important.

The crew continued to receive updates from Mission Control, eager for news about Tony. Most days, the transmissions were hopeful. Tony faced every obstacle with stubbornness and his own special brand of ingenuity, slowly but surely getting ready for his trip to reach the Ares 4 MAV.

Eventually, Tony was all set, having somehow found a way to bring everything he needed in a modified mission Rover. Bucky was both impressed and very proud, his heart racing with excitement when the day for Tony's departure arrived.

Bucky wished that he could have done something — offered more than silent prayers and the unwavering trust he had in Tony's abilities — but the most important fact still remained.

Tony was one step closer to being rescued.

Being stuck on _Hermes_ while Tony drove 3200 kilometers across the rocky Martian landscape was beyond frustrating. There was literally nothing Bucky could do to help. He tried to remain positive, especially when the bad reports arrived, telling of sandstorms and other complications. Bucky thought he would go mad from worry.

"He'll pull through."

Bucky flinched and looked up from the console in front of him — the words he had been staring at for several minutes, futilely hoping they would change into something more uplifting. Romanoff was standing in the doorway to the bridge, her arms crossed over her chest.

"What?" Bucky asked.

"Stark," she said, walking closer. She placed a hand on the crumpled headrest of Bucky's chair, just shy of touching him. "He'll get to the MAV. You know he will."

Bucky swallowed, forcing himself to take a deep breath and then nod. "Yeah, I know." His gaze travelled back to his screen and the newest report from Houston. The sandstorm was bad and Tony would lose precious time if he drove around it, but passing through was impossible.

"He'll make it," Romanoff repeated, her hand slipping down to rest on Bucky's shoulder. "We'll bring him home."

Something tight and heavy in Bucky's chest loosened, ever so slightly. He turned his head and looked up at Romanoff, smiling when he saw the conviction in her eyes.

"Yeah," he agreed, "we'll bring him home."

Somehow, through some kind of miracle, Tony arrived to the Ares 4 site in one piece. _Hermes_ was still over a month away, which would give Tony ample time to modify the MAV according to NASA's specifications.

Bucky suspected that the following month would be one of the longest of his life, but since Tony was waiting on the other end, Bucky knew it would be worth it.

They were almost there — just one more month.

Bucky hovered anxiously behind Romanoff's chair, staring over her shoulder. Romanoff remained impressively unaffected by his presence — something Bucky definitely wouldn't have been able to pull off in her position — and simply kept typing out the necessary commands.

They were close enough to Mars that they could contact Tony directly, and Houston had finally given them permission to do just that. Romanoff set up the connection with her usual efficiency, but there was an unmistakable urgency in her movements that belied her calm.

Not that Bucky could blame her, seeing as he was practically vibrating with tension himself. The thought of having a direct line to Tony — no matter if it was text only — was enough to leave Bucky breathless with anticipation. He shoved his hands into his armpits to keep them from shaking, but no matter how hard he tried, he couldn't seem to get his heart to stop racing.

Romanoff threw him a quick, reassuring smile before she started typing. Bucky watched the screen, shoulders raised and back tense.

**_[19:22] ROMANOFF:_ ** _Hello, Stark._

Bucky's heartbeat echoed loudly in his ears. An agonizing couple of seconds passed before the reply came.

**_[19:23] MAV:_ ** _Romanoff! Hi! Is NASA finally letting you talk to me directly?_

Bucky's breath stuttered out of his chest, a soft, half-choked noise of relief slipping free without his consent.

**_[19:24] ROMANOFF:_ ** _Yes, they gave permission an hour ago. We're close enough to speak almost in real time. The system is up and running, but I'm still performing some tests._

It was Tony. On the other end of those pixelated letters was Tony, somehow alive, against all odds. Bucky didn't know whether to smile or cry, and eventually ended up doing neither. He simply stood there, quietly reading Romanoff and Tony's conversation.

**_[19:25] MAV:_ ** _NASA was really stubborn about not letting us speak, huh?_

**_[19:25] ROMANOFF:_ ** _Psychiatrist's orders._

**_[19:26] MAV:_ ** _What? They think I'm going to start cursing at you all for leaving me on Mars to die?_

Romanoff let out a snort that was clearly more of a laugh than anything else. Bucky couldn't embrace the joke, however — not when he still felt the occasional wave of guilt.

**_[19:27] ROMANOFF:_ ** _Your sense of humor is atrocious._

**_[19:27] MAV:_ ** _Made you laugh, though, didn't it?_

A fond smile spread on Romanoff's lips. As she kept typing, Bucky leaned a little closer, as if that would somehow bring him closer to Tony, too.

**_[19:28] ROMANOFF:_ ** _It's nice to hear from you again, Stark._

**_[19:29] MAV:_ ** _I think that's my line. Also, I hope you've taken good care of my ship._

**_[19:30] ROMANOFF:_ ** _It's not yours just because you helped design it._

**_[19:30] MAV:_ ** _Details. Now, how are you all doing?_

Bucky couldn't help wanting to cling to every word that appeared on Romanoff's screen. This frail line of communication with Tony felt like a miracle after so many months without him. There had been emails, sure, but this was even better. It felt more real.

**_[19:31] ROMANOFF:_ ** _We're fine. So is the ship. And before you ask: yes, Barnes is here, hanging over my shoulder._

Bucky straightened and quickly took a step back. He couldn't say if he felt guilty or embarrassed — perhaps a bit of both.

"I wasn't criticizing you," Romanoff said calmly. Her gaze was full of compassion when she looked up at him. "He's as eager to talk to you as you are to talk to him." She gestured towards the screen, just as Tony's next message arrived.

**_[19:32] MAV:_ ** _I was hoping you'd say that. Is there any chance you'd lend him the keyboard for a minute or two?_

Romanoff was far too mature to say "I told you so" out loud, but the eyebrow she raised did so all the same.

Bucky had to clear his throat before his voice was stable enough to be of use. "Can I? Speak to him, I mean."

Instead of replying, Romanoff got up from her chair and gestured for him to go ahead. After giving his shoulder a pat, she even went as far as to leave the bridge — something Bucky was ridiculously grateful for. He quickly slid into the seat Romanoff had just vacated and placed his hands on the keyboard.

They were shaking.

Bucky swallowed, trying desperately to push down the emotions threatening to burst free. Most of them were good, but he didn't have time for a breakdown — not when Tony was _right there_ , on the other side of the screen. Bucky could speak directly to Tony for the first time in over a year.

After a slow, deep breath, Bucky started typing.

**_[19:35] ROMANOFF:_ ** _Hi Tony._

He only had to wait for roughly twenty seconds before he got a reply, but those were nerve-wracking seconds.

**_[19:35] MAV:_ ** _Doc. You okay?_

A croaked laugh echoed over the bridge and Bucky had to close his eyes to soothe the sting behind his eyelids. He couldn't help smiling, despite the ache in his chest and the furious, nervous beats of his heart. His fingers fumbled over the keys.

**_[19:36] ROMANOFF:_ ** _Woudl it be too cheesy if i said "i am now"?_

**_[19:37] MAV:_ ** _Yes. Horribly cheesy. Ridiculously cheesy. But I forgive you._

Bucky's throat constricted, his teeth clenching so hard it hurt. God, how he had missed Tony. He stared helplessly at the words on Romanoff's screen, barely able to breathe through the relief. Tony was alive. Tony was right there.

Before Bucky had time to reply, another message from Tony arrived.

**_[19:37] MAV:_ ** _For everything, Bucky. I forgive you. You hear me?_

As expected as those words were — Tony had told Bucky that this wasn't his fault time and time again — they had never felt more real than they did in that moment.

The sob was torn from Bucky much like his screams had been, shortly after he thought Tony had died. The relief and gratitude was simply too much, forcing him to hide his face in his hands, elbows braced against the console in front of him.

He knew now wasn't the time to start crying, but he couldn't help it. His shoulders shook with the effort to hold back his sobs, his throat tight and aching.

Tony was alive.

Tony forgave him.

Everything would be fine. Tony was _alive_.

Bucky ran both hands through his hair and let out a trembling exhale. He kept his eyes closed, not daring to look up. He allowed himself several precious seconds before he glanced at the screen again, not surprised to see that Tony had written two more messages.

**_[19:40] MAV:_ ** _Bucky? You there?_

**_[19:41] MAV:_ ** _Everything okay?_

Bucky cleared his throat and wiped the tears away with his sleeve, knowing it would be cruel to make Tony wait.

**_[19:43] ROMANOFF:_ ** _im here_

The delay gave Bucky enough time to take a deep, cleansing breath before Tony's answer arrived.

**_[19:44] MAV:_ ** _Are you okay?_

**_[19:44] ROMANOFF:_ ** _im fine_

That might have been a white lie — Bucky could still feel the tears burning and his hands were far from stable — but it was getting easier to breathe. He _would_ be fine, as soon as Tony was back on board _Hermes_ with the rest of them. Nothing else mattered but that.

Now, more than ever, Bucky was determined to do whatever it took to rescue Tony.

**_[19:45] MAV:_ ** _You sure?_

Bucky read Tony's message and managed a faint smile.

**_[19:46] ROMANOFF:_ ** _im sure._

**_[19:46] ROMANOFF:_ ** _im just so relieved_

The ship was humming steadily around him and Tony was closer than he had been in over a year. Slowly but surely, Bucky's shoulders began to relax.

**_[19:47] MAV:_ ** _That makes two of us._

Bucky exhaled, a faint smile spreading on his lips. He was still worried — there was no telling what might happen during the actual rescue mission — but that didn't stop the hope from growing inside his chest. If all went well, he would see Tony again soon.

Bucky ran a hand through his hair before reaching for the keys again.

**_[19:48] ROMANOFF:_ ** _Just hang in there. We'll bring you home. We wont fail you this time_

Bucky wasn't sure if Tony actually needed the reassurance — he seemed admirably calm considering the circumstances — but Bucky wanted to give it all the same. He needed Tony to know that they were going to set things right. They were going to save him.

Tony's reply held just as much conviction as Bucky's words had.

**_[19:48] MAV:_ ** _I know._

 

**Notes for the Chapter:**

> For those of you who haven't read the book or seen the movie, it was heavily implied that it was the _Hermes_ flight director who leaked the information to the crew. In this story, that would be Peggy Carter, because she would definitely not stand for the shit NASA was trying to pull, even if it cost her her job.
> 
> I had so much fun writing that conversation between Bucky and his sister <3
> 
> The next chapter will be the actual rescue, and then there's the epilogue left. Almost there!


	5. The Rescue

 

* * *

 

Steve gathered them in the Rec the day before the rescue mission. The crew had halted _Hermes_ ' rotational gravity in preparation for the coming operation and floated leisurely in zero-g, eyes on their commander.

"Everybody ready for tomorrow?" Steve asked.

"I'm ready," Barton replied. "Or as ready as I can be."

Romanoff clarified at Steve's raised eyebrow. "We've gone through all the simulations of possible scenarios, but there might still be some catastrophic error we can't predict."

"Or do anything about," Barton interjected. "But, other than that, we're good."

Bucky honestly wasn't sure if he should laugh at Barton's casual attitude or not. It seemed like bad taste considering the severity of the situation, but he knew that sarcasm and wit was how Barton handled stress. No one would be more upset if he failed than Barton himself.

"The course is perfect," Thor picked up, possibly in an attempt to change the subject before Steve's displeased frown turned into verbal reprimands. "We are within one meter of the projected path and two centimeters per second of projected velocity."

That would certainly make Bucky's job easier. He hooked the toe of his shoe underneath the rec room table to stay somewhat motionless when Steve's gaze eventually found him.

"Bucky?"

"I'm all set," Bucky replied. "The tethers are linked and spooled in Airlock 2, and I've prepped my suit and the MMU."

"Good." Steve looked at the crew. His expression was the calm, focused one Bucky was used to seeing before complicated missions, and he took a lot of comfort in that. Steve could make even the most hopeless situation seem manageable. "The plan is fairly obvious and you all know your places. Barton pilots the MAV while Romanoff will monitor the ascent."

Barton and Romanoff nodded in confirmation.

"Bucky and Thor will be stationed in Airlock 2. Since we don't want any last-minute problems or glitches with the suits or the airlocks, you will be suited up with the outer airlock door open before the MAV even launches," Steve said to Bucky and Thor. "You'll have to wait for almost an hour, but it's our best option. Once we reach intercept, Bucky will get Stark."

Bucky couldn't deny that he was nervous enough to feel his heart race. This mission was both dangerous and complicated, and there was so much at stake.

"Thor," Steve continued, "if all goes well, you're pulling Bucky and Stark back aboard with the tether. If not, you will be Bucky's backup."

"Understood." Thor nodded, expression severe.

Bucky cleared his throat. "Tony... he's probably going to be in bad shape when we get him on board. The g-forces during the launch might cause broken bones or internal bleeding."

A small smile appeared on Steve's lips. "Good thing the person with him will be our doctor, then."

Those words caused a dizzying swoop in Bucky's stomach. He couldn't quite say if it was joy at knowing that he would be the first one Tony saw once he made it back aboard _Hermes_ , or fear of failing and causing Tony harm.

He swallowed all the same, giving Steve a firm nod.

Steve exhaled, the faint smile lingering. "Your schedules have been cleared so there's not much else to do but wait. Check your gear one last time if you need something to do — we need to be at our best tomorrow — but try to sleep if you can."

That was a tall order, but the crew nodded in unison. Bucky, for one, knew that sleep was going to be difficult. There were far too many thoughts racing through his head and more nervous tension than he could possibly dispel.

"We will manage," Thor said, steady and sincere, his tone leaving little room for argument. "We will rescue Tony tomorrow."

Steve's smile grew stronger, his shoulders relaxing ever so slightly. "Yes," he agreed, "we will."

Bucky took a deep breath before knocking on Steve's door, floating awkwardly in the hallway just outside. He didn't have to wait long before Steve opened, a flicker of surprise visible in his eyes.

"Hey, Buck. Everything okay?" The softness in Steve's voice made something in Bucky's chest clench and he had to focus to push past the tightness in his throat.

"Yeah, I just..." He looked away, fingers grasping the doorway to keep himself from drifting away. "I wanted to say thank you."

"What for?"

Bucky met Steve's gaze, making sure to smile. "For everything. For not pushing when I needed space, but being there when I couldn't stand being alone. I can't imagine what kind of asshole I must have—"

"Bucky," Steve interrupted, his responding smile patient, "it's okay. End of the line, remember?"

"Yeah," Bucky croaked.

"You don't have to thank me." Steve reached out, hand landing on Bucky's shoulder. There was so much comfort and familiarity in that gesture that Bucky felt himself relax.

"I know," he replied, "but that doesn't mean I shouldn't. I don't want you to ever doubt just how much our friendship means to me."

Steve shook his head, his gaze warm and fond. "That will never happen, don't worry." His hand moved to playfully ruffle Bucky's hair instead. "Now go get some sleep, Dr. Barnes — that's an order."

Bucky laughed and ducked out of Steve's reach, running a hand through his hair to sort out the mess Steve had caused. He should probably have it cut — it was longer than usual after so many months in space — but hadn't quite found the energy to do so while busy worrying about Tony and the imminent rescue. On the way home, perhaps.

"I'll do my best, Commander," Bucky deadpanned. The mock salute he added afterwards made Steve roll his eyes, but the amusement on his face was well worth it.

Bucky was grinning all the way back to his cabin.

No matter how hard he tried, Bucky couldn't find a word to describe what he felt when they were but minutes away from mission start. Terror was too frightening, somehow, and anticipation too uncomplicated. Hope was too innocent and fear too mild. As Bucky floated in the open airlock, Thor beside him, Bucky was too full of emotions to catalogue even a single one. The pit of his stomach was tied into knots, his breaths trembling just as much as his hands.

He barely heard Steve and Romanoff over the comms, going through the preflight checklist. Bucky was too distracted by the loud thump of his own heartbeat and the faint taste of nausea at the back of his throat.

This was their only chance to save Tony, and Bucky wasn't sure if he had ever been so nervous in his entire life. So many things could go wrong. So many ways for this to end catastrophically — for all of them.

A part of Bucky wished that he could simply close his eyes and open them once it was all over — when Tony was safely back on _Hermes_ with the rest of them. Bucky wasn't sure how he was supposed to maintain his calm long enough to actually complete the catch.

Steve's voice filtered in through the haze, calm and steady despite the nerve-wracking situation.

"Remote command," he said.

"Go," Barton responded.

"Pilot," Steve requested.

Bucky should have been prepared for what came next — he knew the preflight checklist in his sleep — but his heart still seemed to stutter when another voice joined them over the comms, one Bucky hadn't heard in over a year.

"Go," Tony replied.

For a split second, it felt like everything around him was spinning. Since Bucky was floating in zero-g, that was a physical possibility, but he knew he hadn't moved, his fingers gripping one of the handhold hard enough to make the metal groan. He sucked in a sharp breath, trying to get the painful surge of relief under control. Hearing Tony's voice again after so long was indescribable.

A part of Bucky still couldn't believe this was happening — Tony was so close. Within two hours, this would all be over. This entire nightmare would finally come to an end.

Bucky flinched when he felt a hand land on his shoulder, looking at Thor in surprise.

"Recovery?" Steve's voice was sharp over the comms, as if that wasn't the first time he'd said the word.

Shit.

Bucky had been so wrapped up in his own head that he'd missed his cue.

"Go," he hurried to respond, even if he wasn't entirely sure how prepared he was.

Steve continued without delay. "Secondary recovery."

"Go," Thor replied, and gave Bucky's shoulder a squeeze. Their helmets once again made it impossible to see facial expressions, but Bucky was fairly certain that Thor was offering him one of his comforting smiles.

Both Bucky and Thor remained silent while Steve finished the preflight protocol together with Mission Control. Thor's hand remained on Bucky's shoulder, a steady weight that helped a lot more than Bucky thought it would. He focused on his breathing, slowly but surely pushing down the nerves and rolling emotions. Only when Bucky's shoulder lowered did Thor remove his hand, and Bucky reminded himself to thank him later, after the rescue mission was over.

"We're four minutes from launch," Steve reported, voice clear. "How are you doing, Stark?"

There was a relieved yet slightly nervous laugh over the comms. "Eager, but a little terrified, if I'm to be honest with you."

Bucky closed his eyes, exhaling slowly. Just listening was more than enough.

"I hope that's not a jab at my flying skills, Stark," Barton cut in. There was enough humor in his voice to soften his words, however.

"Seriously, Maverick, no barrel rolls." Tony must have been grinning, going by the lighthearted tone.

"You take all of the fun out the job, Stark," Barton replied. "Maybe I should just leave you where you are."

That was an empty threat and they all knew it. Steve seemed to find it appropriate to interrupt either way.

"Tony, remember that you're going to be pulling a lot of g's during this launch." Steve spoke a little softer now, kinder. "It's okay to pass out since Barton will handle the flying."

"Sure thing," Tony replied smoothly. "I'll just sit back and relax. If anything happens, Doc will fix me up when I get there, right?"

There was a brief silence over the comms, expectant and heavy. Bucky swallowed, almost choking from how dry his throat was. There was a sharp pang of panic, but he ruthlessly shoved it down.

"Yeah," he managed to croak. "I've got you, Tony."

Bucky knew he wasn't imagining the slight hitch in Tony's voice. "That's all I need to know."

The grief and the guilt rose in a last, desperate attempt to throw him off balance, but Bucky was ready this time. He couldn't risk losing focus now — too much was at stake. He was not going to fail Tony a second time.

"We'll get you through this, Tony," Bucky said, slightly surprised by the strength in his own voice. It suddenly felt easier to breathe, and he made sure to take a deep lungful of air. "Just hang in there."

A second passed before Tony replied, and even if it was just one word, it sounded choked. "Okay."

Bucky didn't blame him in the least.

Thor and Bucky waited while Barton and Romanoff initiated the launch. There wasn't much either of them could do until Tony was within reach to be grabbed. Bucky closed his eyes, praying softly under his breath while he listened to Barton and Romanoff rattle off velocity and engine power levels. The MAV's ascent seemed to be going slower than calculated. Considering the adjustments Tony had been forced to make to the MAV, that wasn't unexpected — things like that could easily cause unexpected malfunctions.

The biggest problem was that a delay during the launch would inevitably affect the intercept.

After a soft exhale, Bucky turned to catch Thor's attention, making sure that his next couple of words were only heard between the two of them.

"Thor, if I can't reach Tony, I want you to release my tether."

There was a stunned silence.

"Doctor, you know I can't," Thor replied, tone serious, if with a hint of regret. "The commander has forbidden you to do the catch without a tether."

"Steve's not here, is he?" Bucky said, feeling a curl of desperation. "I'm just saying that if I need an extra couple of meters, you should cut me loose. I still have the MMU. I can make the catch and get back without a tether."

"James—"

"It's _my_ choice," Bucky interrupted. "It's _my_ life I'm risking and you can't say I'm not—"

"I will not release you tether." Thor's words held enough finality that Bucky knew there was no point in arguing. "It isn't just your life, Doctor. If you were to miss, no matter how small the risk might be, how do you think the commander and Tony would feel?"

A lump formed in Bucky's throat and he couldn't deny that it tasted a whole lot like guilt.

"I understand why you are so desperate to rescue him," Thor continued, softer now. "I admire your bravery, but you should be less eager to throw your own life away — especially when you don't have to."

Bucky gritted his teeth, not sure if he was more angry with himself or Thor.

"But if I miss—"

"You won't," Thor said firmly. "I have faith in you, and so does Tony."

"Yeah, let's just hope I live up to it," Bucky muttered.

Thor didn't reply, but that might have been just as well.

Just as Bucky had expected, the MAV was no longer following the plotted trajectory. Tony had made it into orbit, but the delay had been too great. Bucky and Thor waited in tense silence while Romanoff calculated the numbers. Tony wasn't responding, but Bucky forced himself to stay calm — Tony had, in all likelihood, simply fainted from the immense pressure of the launch.

"Intercept velocity will be eleven meters per second," Romanoff reported.

Bucky felt some of the tension he held uncoil. "That's manageable."

"The distance will be..." Romanoff fell silent, and when she continued, her voice was tight. "Sixty-eight kilometers."

" _What_?" Bucky blurted out. "Are you fucking kiddin' me? _Kilometers_? Even sixty-eight _meters_ would be—"

"We'll figure it out," Steve interrupted, steel and determination in his voice. "Thor, Bucky, stand by. We'll get back to you when we have a solution."

Bucky gritted his teeth. "Copy."

"Copy that, Commander," Thor said, sounding far too calm for Bucky's liking. He knew he was being unfair, though — Thor was probably as worried as he was.

Bucky listened with half an ear while Steve, Romanoff, and Barton tried to figure out how to limit the projected distance between them and the MAV, his thoughts spinning. Sixty-eight kilometers — even _one_ kilometer — was too far away for Bucky to make the grab, tether or no tether. If he missed, Tony would be trapped inside the MAV, floating helplessly in space until his oxygen ran out. It sounded like a horrible way to die, and Bucky just couldn't let that happen. They just had to figure out how to prevent it.

As if on a cue, Steve's voice echoed out over the channel.

"Bucky, we're going to use the attitude thrusters to get us within intercept range." There was an unmistakable tightness in Steve's voice as he spoke. "That should get you close enough for the grab."

Usually, the attitude thrusters were used to make smaller adjustments to their course, but if they turned them all in the same direction at the same time, Bucky supposed they could push _Hermes_ quite some distance.

"I sense a 'but' in there somewhere," Bucky replied, too tense to start celebrating yet.

"Well, we'd reduce the distance, but burning those jets will increase our speed."

Bucky closed his eyes, taking a deep breath. "So we'll be close enough, but we'll be coming in too fast instead."

"Pretty much," Steve replied. "But we have thirty-nine minutes to figure out how to slow down."

"Better get to it, then." Bucky felt desperation grow at the back of his throat, but swallowed it down. This wasn't over yet — they could still fix this.

"I'll let you know what we come up with," Steve said. Bucky couldn't help but marvel at Steve's stubbornness. It would be wrong to say that he was unfazed by what was happening, but he was clearly far from ready to give up. Then again, that was probably why he had been made commander.

Not for the first time, Bucky thanked his lucky star that Steve was with him on this — he wasn't sure how he would have handled everything if he hadn't been.

"MAV to _Hermes_."

Bucky flinched when Tony's voice suddenly filled his ears. They had about twenty minutes left before intercept.

"Stark!" Steve sounded relieved. "Is that you?"

"Affirmative, Commander." There was too much strain in Tony's voice, his words a little slurred. "What's up?"

Steve clearly ignored Tony's question for now. "How are you feeling?"

Tony let out a hoarse laugh, but seemed to regret it a moment later going by his pained groan. "Still alive, it seems. Might've cracked a rib, though. My chest hurts."

"We'll fix that once you get here," Steve reassured. "Right now we need to focus on getting to you. There was some trouble during the launch."

"Doesn't surprise me," Tony replied. "You should see the state of the MAV — I'm amazed it flew in the first place." Before Steve had time to answer, Tony continued. "So, how bad is it?"

"We were able to adjust the trajectory, but are now coming in too fast."

"How fast?"

Steve's sigh was audible over the comms. "Forty-two meters per second."

"Well, shit," Tony said, rather eloquently. "That's not going to work. Doc, what speed can you work with?"

Bucky couldn't help but be amazed by Tony's ability to compartmentalize. He had to be disoriented and in pain, but immediately switched gears to help solve the situation. Granted that his survival depended on it, but his determination was quite admirable.

"Twenty-five meters per second, but it would be a close call." Bucky had run the numbers while Steve, Romanoff, and Barton had been working on a way to slow them down. There was one catch, though. "If I go out untethered," he added.

"No," Steve and Tony replied in unison. Had the situation not been so grave, Bucky might even have found that a little hilarious.

"But it would—"

Tony interrupted Bucky before he got any further. "I have an idea, actually. If I poke a hole in the glove of my EVA suit the release of the oxygen would function as a thruster. I could fly myself closer to you."

"I think Stark might have left his brain back on Mars," Barton said. "Or scrambled it during the launch."

Bucky was glad that he wasn't the only one who thought that Tony was a little too careless with his own safety. At least Bucky would have an MMU to carefully adjust his course if he went untethered — Tony would be flying more or less blind, pushed forward by a pressure he couldn't adjust or aim properly.

"It's not _that_ bad of an idea," Tony defended.

"It's a horrible idea," Romanoff deadpanned.

Steve seemed to agree, his voice flat. "Would you be able to control it?"

"Well, theoretically, since my hand would be the thruster." Tony sounded just a little too enthusiastic when he continued. "I admit that it could prove fatal, _but_ , on the plus side, I would get to fly around like—"

"It's not happening, Tony," Steve said. "We'll figure something else out."

"You ruin all my fun, Rogers."

Despite the tenseness of the situation and the worry squeezing Bucky's chest to the point of pain, hearing Tony joke startled a laugh out of him. He had to grit his teeth to stifle the sob it almost evolved into. God, how he had missed Tony.

"Actually, Commander," Romanoff cut in, "we might be able to use that."

"Stark shooting himself out into space like a deflating balloon?" Barton sounded suitably dubious.

"No," Romanoff responded, "using atmosphere as thrust — that could help slow our intercept velocity."

There was a brief silence.

"Keep talking," Steve said.

If anyone had told Bucky that he would find himself in a situation where he would deliberately blow a hole in the hull of the spaceship he was travelling in, using a homemade bomb made by a Norwegian astronaut, he would have told them they were insane. He would have thought _himself_ to be insane.

But, as it turned out, one had to do desperate things when saving a crewmate from certain death.

The plan Steve, Barton, and Romanoff had come up with was certifiably insane. Bucky knew so for a fact since even _Tony_ had argued against the dangers, and he was notoriously careless when it came to virtually everything. Or perhaps he saw it differently when it was others who put their life on the line.

The plan was fairly simple, yet ludicrously dangerous.

If they opened the airlock at the front of the ship, the escaping oxygen would function like thrusters and slow their intercept velocity to a much more manageable thirteen meters per second. The problem being that airlocks weren't _meant_ to open during flights with the intention to suck out all the oxygen in the ship — there were, in fact, several fail-safes to _prevent_ such a situation. There was no remote way to open both of the airlock doors at the same time and doing so manually meant being sucked out into space together with the oxygen.

Steve's solution was to have Thor build a bomb and blow one of the doors open.

Bucky had felt a need to point out that setting off a bomb in a spaceship was a _very_ bad idea. Still, it was the best one they had.

They would seal off the rooms that still required oxygen — the bridge and reactor room — and destroy the inner airlock door rather than the outer one, to maintain the shape of the hull. First, someone had to enter the airlock, depressurize it, and open the outer door and mechanically lock it into place — a task that naturally fell on Bucky as their EVA expert. Once Romanoff and Thor then blew the inner door open from a safe distance, the oxygen would rush out without risking one of their crewmembers in the process.

The only slight problem being that after opening the outer airlock door, Bucky would be unable to reenter the _Hermes_ the usual way. He would have to crawl along the hull of the ship to Airlock 2. Tony had protested loudly to this idea, but Steve had ignored him. Bucky couldn't say that he was looking forward to the danger he would put himself in, but to save Tony, well — he would do whatever it took.

On the way to the frontal airlock, Bucky floated past Romanoff as she was fiddling with one of the lighting panels — she and Thor had figured out a way to use it as the remote detonator, apparently.

She looked up, her smile holding a sharp edge that had to be nerves. "Be careful out there, Barnes."

"I will," he replied, giving her a sloppy salute — much else was difficult in the EVA suit.

"I would prefer if he didn't do it at all," Tony cut in, displeasure evident in his voice.

Romanoff snorted, her smile growing a little stronger. "You just sit tight, Stark, and let us be the heroes this time." Tony sucked in a breath to reply but Romanoff kept talking right over him. "You know, it would probably be a lot safer for him if you didn't distract him with your talking."

The comment was bordering on mean, but not untrue — Bucky's heart still skipped a beat whenever he heard Tony's voice over the comms. It _was_ distracting, and he had to focus on climbing.

"I'll be careful," Bucky said, hoping to reassure. "See you soon."

There was a brief silence before Tony answered, his voice a little frailer. "Yes, see you soon."

As much as Bucky wanted to stop Tony from sounding so worried, this was one of the times when he couldn't. He had to do this, even if it was dangerous.

So Bucky simply gave Romanoff a quick wave in response to her nod, then continued towards the airlock.

Thor was there to open the door once Bucky had finished his little excursion outside and reached Airlock 2.

"All right, Doctor?" he asked as he pulled Bucky aboard.

Despite the slight tremble to his limbs — more adrenaline than exhaustion — Bucky couldn't help but laugh. "I just crawled across the ship after making sure that we'll be able to blow a hole in our spaceship. It's been a weird day."

Thor laughed too, pulling them both deeper into the airlock with the use of the handholds. "Yes, I have to agree." Thor sounded delighted. "I got to build a bomb."

"Steve," Bucky said, still chuckling under his breath, "Thor and I are in position in Airlock 2."

"Copy," Steve replied.

Bucky could have sworn he heard Tony mutter a soft, "Thank fuck for that," a split second later. No one seemed to acknowledge it, however.

"Get tethered and brace yourself for the explosion," Steve continued. "We'll be feeling about one g while the oxygen is rushing out."

"Will do." Bucky pressed himself against the fore wall together with Thor, attaching his tether to one of the anchor points.

He listened while Barton and Romanoff made the final adjustments, his heart picking up its pace. This was it. If this failed, they wouldn't have time to come up with another plan on how to slow down. It would be near impossible to make the catch, but Bucky knew that he would make an attempt no matter what Steve or anyone else said. They had come much too far to give up now.

Romanoff started counting down and Bucky closed his eyes.

The rush of acceleration from the escaping oxygen lasted about four seconds.

Bucky let out a slow breath once it was over and waited for the verdict. As far as he could tell, _Hermes_ hadn't blown up. The question was if they had managed to slow down as much as needed.

"Our distance to the MAV will be twenty-two meters, our expected velocity twelve meters per second," Romanoff reported, voice clipped yet hopeful. "Better than expected."

"Bucky, can you make that work?" Steve asked hurriedly.

"Yeah." Bucky still felt a little breathless, nodding even though no one but Thor could see it. "Yes, I can. I can make it work."

It was close enough — it had to be.

"Stark, did you hear that?" Steve said. "Bucky is coming to get you."

"That's awesome." Tony sounded a little shaky, but Bucky couldn't blame him for that. "I'll just wait here for my knight in shining armor."

Bucky let out a startled laugh while Thor loosely gripped Bucky's tether.

"Good luck, Doctor." There was a tense edge to Thor's voice — brought on by the severity of the situation, no doubt — but there was warmth and sincerity too.

"Thank you." Bucky took a deep breath, braced his feet against the wall, and pushed out of the airlock.

The first couple of seconds out in open space were disorienting, but Bucky quickly got his bearings — he only had a short window of time before _Hermes_ and the MAV would drift too far away from each other. He had to locate Tony before that.

"Visual on the MAV!" Bucky couldn't contain the eagerness in his voice when he caught sight of the spacecraft. Urgency was thrumming through him, his focus narrowing down to the task at hand.

Just as they had been warned, the MAV was a shadow of its former self, jagged with edges where components had been removed. The entire front was open, covered only with a tarp that had loosened sometime during the flight. Bucky had to agree with Tony — it was a miracle it had been able to take off in the first place.

"Sweet Jesus, Tony. What on earth did you do to the MAV?"

Tony laughed. "You should see what I did to Mr. Hot Wheels."

"To who?" Bucky frowned, not entirely in tune with the conversation — he was more concerned with steering himself closer to the floating MAV. A burst of the MMU's thrusters and Bucky got steadily closer.

"The rover."

Trust Tony to name one of the mission rovers — and pick such a ridiculous one to boot.

"Five point two meters per second," Romanoff radioed. "Keep going."

A calm focus had settled over Bucky, making him only vaguely aware of the nervous twist at the pit of his stomach. He had trained for this many times, and he felt more confident than he thought he would as he made his way towards the MAV.

He kept listening to Romanoff's reports of his progress, replying and adjusting his approach accordingly, almost without conscious thought. Only when he was able to reach out and grab a hold of the MAV did the rest come rushing back.

"Contact!" he declared, suddenly aware of the loud beats of his heart and slightly elevated breathing. He pulled himself closer, holding on the MAV with both hands. "Firm contact!"

"Doctor, you have one hundred and ninety-six meters of tether left." Thor's voice was startlingly loud after the strange silence Bucky had been enveloped in. "Enough for fourteen seconds."

Bucky didn't waste time. "Copy," he said, before pulling himself to the opening, looking down into the MAV. He caught sight of Tony, sitting strapped down in his chair.

"Visual on Tony." Bucky had no idea how he managed to make his words sound so stable — he felt like bursting into tears from relief.

"Holy shit," was Tony's only reply, wobbly and half-choked.

"It's okay, sweetheart," Bucky said, quickly pulling himself into the ship to reach Tony. He needed to latch them together before Thor could start pulling them back towards _Hermes_. "I've got you."

"Just... give me a minute." Tony laughed. "You're the first human I've seen in eighteen months."

Bucky couldn't imagine what that had to feel like.

"Don't have a minute to spare, darling," he replied apologetically. "We've only got about eleven seconds before the tether runs out."

He kicked off against the wall, colliding clumsily with Tony and his chair. Tony desperately grabbed his arm, keeping him from bouncing away again.

"Contact with Tony," Bucky said aloud for the benefit of the rest of the crew, then much softer for no one but Tony. "I've got you. It's okay."

"Eight seconds," Thor warned.

"Copy," Bucky replied and quickly latched him and Tony together with the tether clips on their suits. "Connected."

Tony's hands fumbled when he released the straps tying him to the chair, but he got it done. "Restraints off."

Bucky knew they only had a couple of seconds left, but he found himself smiling all the same. "Let's get out of here, shall we?"

Tony only laughed as Bucky braced his feet against the chair and kicked off, taking them both towards the opening of the MAV. Bucky grabbed the edge once they were close enough, his metal fingers closing around it with a soft whirr. He pulled as hard as he could, giving them an extra push through the hole.

"We're out," he reported, heart in his throat and Tony's helmet bumping gently against his. Tony had a firm, slightly panicked, grip around Bucky's suit, and Bucky could hear his rapid breathing over the comms.

"It's okay," he whispered, soft and soothing. "I've got you, sweetheart. I'm not letting you go."

The reply he got was a choked gasp, heartbreakingly close to a sob. "I know," Tony replied.

 

**Notes for the Chapter:**

> I know some of you wanted the kiss to happen in this chapter but I didn't have room for it. So you'll have to wait for the epilogue for that, I'm afraid! It's a pretty lengthy one, though, with lots of fluff and other nice things.
> 
> Soon done, my lovelies!


	6. Epilogue

 

* * *

 

Tony's return to _Hermes_ was far from glamorous.

First, the ship was still without oxygen everywhere but the bridge and reactor room, so there were no heartfelt hugs or welcome back kisses. Bucky, Tony, and Thor couldn't remove their clunky EVA suits, and Steve, Barton, and Romanoff were stuck inside the bridge until the front airlock was closed again and the ship had re-pressurized.

Second, Tony was injured, though he clearly tried to hide it. Judging by the suspicious silence, he had shut off his mic to keep Bucky from hearing how much pain he was in.

Bucky floated Tony to his own quarters, which doubled as the sick bay, while Thor went to close the airlock. It still took several long minutes before it was safe to remove their helmets and suits, and Bucky tried not to flinch when they did. It wasn't just the fact that Tony smelled rather foul — showers were hard to come by on Mars — but how gaunt and tired he looked. Bucky had known that Tony would be malnourished once he made it back to them, but he hadn't been prepared for just how bad it would be. Tony's scruffy beard and unevenly cut hair didn't help the overall look in the least.

"Your hair is longer," Tony said, voice soft and frail with enough joy to make Bucky's breath catch. "I like it."

Bucky managed a trembling smile and gently stroked Tony's cheek with his thumb — something that made Tony's eyelids flutter closed in bliss.

"Let me get you checked over, okay?" Bucky whispered, heart squeezing when Tony pressed his cheek against Bucky's fingers, no doubt touch-starved after so many months alone on Mars.

Tony nodded, but still whined from disappointment when Bucky pulled his hand back. As heartbreaking as that was, Bucky focused on making sure Tony didn't have internal bleeding — that surely took priority.

Thankfully, Tony had gotten away with nothing more than two broken ribs, which was fairly light considering the circumstances.

The entire time Bucky worked, Tony kept staring at him. It wasn't bad staring, but rather the kind that seemed awed and just a little bit dazed — fully expected after eighteen months without another living soul in sight, Bucky decided.

As soon as they were able, the rest of the crew came to welcome Tony back. Suddenly the room was crowded with people and noise, and Tony seemed a little overwhelmed, though not necessarily in a bad way. His grin was wide enough to look slightly painful, but that might just have been a side effect from how haggard he looked.

Eventually, Bucky shooed them all out and gave Tony enough painkillers to make him able to move without flinching too badly. He then gently steered Tony towards the shower, trying not to notice how he could feel the bones in Tony's shoulder without even trying. Tony's diet on Mars had been far from healthy, but they could correct that now — _Hermes_ had more than enough food to last them the trip back to Earth.

It was only once Tony had disappeared into the shower that the gravity of what they had just done hit Bucky full force.

They had rescued Tony. Against all odds, Tony had made it off Mars in one piece. He was _safe_ and _alive_ and _right there_. It was almost too good to be true.

Before he knew it, Bucky's breath hitched into a sob, months of tension and worrying rushing to the surface. He felt so _relieved_ that he simply couldn't hold back the tears. Tony was back with them, shaken and injured, yes, but no longer trapped alone on a deserted planet.

Everything would be fine.

Bucky gave himself five minutes before he forced himself to stop crying. It wasn't that he felt embarrassed or guilty, but because crying in zero-g was, well, _disorienting_. The water clung to his skin unless he dried it off, and it was just an altogether weird experience.

So he wiped his eyes with the sleeves of his shirt and busied himself with tidying up after his examination of Tony. His hands were shaking the entire time but there seemed to be no curbing the smile on his lips.

Tony was safe. Tony was _alive_.

"Doc?"

Bucky looked up to find Tony floating in his doorway. He had on nothing but underwear and a bathrobe, everything else probably proving too painful to put on considering his broken ribs. Tony still looked far too thin, but seemed more alert now that all the dirt had been removed. He had obviously not taken the time to shave, though, or done something about the mess of hair on top of his head.

"Your eyes are red. Have you been crying?" Tony asked, brows furrowed.

"Only a little," Bucky replied, seeing no reason to hide it.

Tony hesitated in the doorway, his expression not revealing much of anything. There was a spark of doubt in his eyes, though, and Bucky let out a soft exhale, fairly certain he knew what was wrong.

"Darling," he said, opening his arms in invitation.

Instantly, the hesitation was gone and Tony pulled himself across the room with such carelessness that Bucky winced in sympathy for his ribs. He curled his arms around Tony when they collided, not caring that his hip bumped painfully against the table next to him.

"Easy, sweetheart, easy," Bucky whispered, even as he pulled Tony closer. Tony smelled of soap and toothpaste, and Bucky couldn't help burying his nose in his hair. "Be careful with your—"

"I don't care." Tony's words were muffled against Bucky's shoulders, his hands twisted into the fabric of Bucky's sweater. "Fuck it, Bucky, I really don't care about my ribs right now."

Bucky chuckled, soft and a little brittle. "Well, I do." He kissed Tony's temple. "I only just got you back — please don't puncture a lung the first thing you do."

Tony didn't reply, shaking quietly in Bucky's arms. He felt so frail and vulnerable that there was nothing else for Bucky to do than hold on. He curled around Tony as best he could, cradling him close.

"I've got you," he whispered, lips brushing against Tony's temple. "You're safe."

Bucky didn't know how long they stayed there, floating wrapped up together in his quarters, but he didn't care. He was happy as long as he got to have Tony in his arms, his heart beating close to Bucky's own.

It was Tony who eventually pulled back, but only enough to be able to meet Bucky's eyes. His smile was weak and his gaze tired, but he had stopped shaking by then.

"Hi," he murmured. "Nice to see you again."

Bucky let out a soft laugh, his fingers wandering into Tony's hair. "Yeah, you too." Like before, Tony leaned into the touch like a starving man. "You okay?"

Tony closed his eyes, his breaths shallow — most probably to avoid aggravating his ribs.

"I think I will be," he replied. His eyes were warm when he opened them, his smile growing stronger. "I told you I'd make it off that planet."

"Yes, you did." Bucky leaned forward, just a little, until he could rest his forehead against Tony's. The air between them seemed sweeter, somehow, Tony's breaths a soft whisper against Bucky's lips.

"There's one thing, though," Tony said, words so low that they almost got lost underneath the steady hum of _Hermes_ around them.

"Yeah?" Bucky felt a shiver down his spine, Tony's nose brushing against his.

"I distinctly remember someone owing me a kiss."

Bucky huffed out a laugh, both hands rising to wander into Tony's hair. "Well, we can't have that, can we?" Tony practically _purred_ under his hands, warm and pliant where he pressed up against Bucky.

He didn't wait for a reply, instead angling his head to erase that last inch between them, capturing Tony's lips in a kiss. It was sweet and chaste, just as frail as the breathless joy between them, but Bucky didn't mind. His fingers combed through Tony's hair, making him moan.

Bucky pulled back, lips tingling, and smiled at the blissed-out look on Tony's face.

"Like that?" he asked, a hint of teasing in his voice.

"Yeah," Tony replied, sucking in a deep breath before smiling at Bucky. "Just like that."

Bucky reverently ran his thumb along Tony's cheekbone, then pulled him in for another kiss. Tony met him halfway.

Three days later, when they had gravity back on _Hermes_ and had set their course for home, Steve came to find Bucky in the Rec.

Steve looked more relaxed than he had in months, his smile carefree in a way Bucky had so sorely missed. "So, how are you doing?" he asked, sliding into the seat opposite to Bucky, trying to snatch one of the cards from Bucky's game of solitaire.

Bucky slapped Steve's hand away, but couldn't help smiling. "I'm okay."

"And Tony?" Steve laced his fingers together, momentarily accepting defeat.

That was a slightly more difficult question. Bucky exhaled, looking down at his cards. "He's getting there."

The ribs would take weeks to heal, first of all, but there would clearly be psychological repercussions from having spent eighteen months alone on a foreign planet. Tony was resilient, however, and Bucky was prepared to offer whatever kind of support Tony needed.

"I'm glad to hear that." Steve fell silent, but Bucky could tell that he had more to say. And, sure enough, it only took a couple of seconds before Steve spoke up again. "How's the guilt?"

Bucky looked up, meeting Steve's gaze. He couldn't deny that he still felt at least partially responsible for what had happened, but it wasn't a suffocating weight on his conscience anymore. Not when he remembered how he had woken up that morning, with Tony's arm slung carelessly over his chest and his breaths tickling Bucky's neck.

He gave Steve a smile. "Better," he said, scooping the cards back into the deck.

"Good."

Bucky shuffled the cards, not even asking before he started dealing them out. Steve chuckled in response, but dutifully accepted the hand he was dealt, smiling all the while.

"I'm not going to let you win this time," he warned, deftly sorting his cards.

"All the more fun for me when I kick your ass," Bucky replied.

Steve only reply was a wide, happy grin.

The automatic doors opened with a soft hiss and Bucky stepped into Tony's lab. As he had expected, Tony was bent over one of his numerous projects, intently focused on the thin, twisting wires and complex circuitry. Despite the stiffness in Tony's posture — caused by his still-broken ribs — the sight made Bucky's heart clench. To know that Tony was _there_ , safe aboard _Hermes_ with the rest of the crew, was enough of a relief to leave Bucky breathless.

He made his way to where Tony was sitting and placed a gentle hand between Tony's shoulder blades. Despite Bucky's best intentions, Tony flinched in surprise — then immediately hissed from pain when he jarred his injured ribs. Bucky grimaced in sympathy when Tony dropped his soldering iron in favor of curling his arm protectively against his side.

"I'm sorry, sweetheart." Bucky rubbed his thumb soothingly against the back of Tony's neck. "Didn't mean to scare ya'."

"Hi, Doc," Tony greeted, his voice a little tight. He managed a smile when he looked up at Bucky, though, be it a pained one. "It's okay."

"Pretty sure it's not," Bucky replied, one hand combing through Tony's hair while the other picked up the soldering iron and placed it back in its holder. Tony frowned when Bucky proceeded to shut it off as well. "I came by to remind you that it's time to go to bed."

It was well past 3AM and Bucky knew for a fact that whatever Tony was working on could wait until the morning. Ever since he had returned, Tony had spent more time tinkering than resting, which went against every single one of Bucky's instructions. Given how malnourished Tony was, he needed proper sleep, food, and healthy routines.

Unsurprisingly, Tony seemed to find that difficult to manage, and it often fell on Bucky to remind him.

Tony averted his gaze. "Let me just—"

"No, Tony," Bucky said, firm yet fond, fingers wrapping around Tony's wrists. He tried to ignore how thin they were — that he could feel the bones underneath his thumb, Tony's pulse thrumming against his fingertips. Bucky knew Tony wouldn't appreciate being seen as fragile, but it felt like holding a baby bird. Sometimes Bucky was afraid of touching Tony, especially with his bionic hand, fearing he might accidentally break him. "Bed. Now."

Bucky would carry Tony back to their quarters if he so had to. The dark shadows under Tony's eyes had lessened some, sure, and his color had returned after two weeks of carefully regulated but decent meals, but he was still far too thin — far too weak.

A second passed, their gazes locked, before Tony's shoulders began to lower.

Bucky reached up and caressed Tony's cheek with his metal thumb. "Doctor's orders," he added cheekily.

That earned him an amused snort.

"Just how often are you going to use that line on me, Doc?" Tony was grinning now, allowing Bucky to gently tug him to his feet, mindful of Tony's injuries.

"As often as it takes," he replied.

Tony smiled, but there was apprehension in his eyes — Bucky had seen it more than once since Tony made it back to _Hermes_. Bucky had yet to ask Tony to talk to him about it, not because he didn't care, but because Tony clearly needed more time. Bucky knew that Tony was incredibly guarded when it came to discussing emotions and everything involving Mars was still too raw to be spoken out loud.

He could make an educated guess, though, considering that sleep was what seemed to worry Tony the most. Bucky hadn't noticed any nightmares, but he would be foolish to think Tony didn't have them. Perhaps Tony was experiencing the same fears Bucky had been carrying the past two weeks, that all of this — saving Tony and _finally_ having him in his arms — was nothing but a dream. That the moment Bucky fell asleep, he'd wake up to find that Tony was still trapped on Mars, slowly starving to death.

It was, quite frankly, a completely understandable reason for not wanting to go to bed.

Bucky suspected that the insomnia was also why Tony still hadn't fixed the heating problem in Barton's quarters. There was no doubt that Tony _could_ do it — no one knew the ship better than him — but the fact that the stifling heat had spread to Tony's room, which was next door to Barton's, gave him a reason to share with Bucky instead. Steve hadn't so much as batted an eyelash at the news, probably having expected something along those lines anyway.

As it was, what little rest Tony _did_ get was spent wrapped up in Bucky's arms; it seemed to be the only way Tony _could_ fall asleep.

"Come to bed," Bucky said, taking a step backwards, pulling Tony towards the door.

Tony didn't say no, but he didn't look convinced, either. That wouldn't do. Bucky quickly scrambled for another subject — something to take Tony's mind off whatever was troubling him.

"Let me take you out for dinner," he blurted out, not blaming Tony for the surprised blink he gave in response. The request was a little sudden, to be fair. Bucky stopped walking and tugged Tony close enough to rub their noses together, which always earned him a fond, indulgent smile from Tony. "When we're back on Earth, I mean. A date. I want a proper date."

They might have shared hundreds of meals together already — on _Hermes_ and a couple on Mars — but that wasn't the same.

Tony let out a short laugh, his eyes finally sparkling with their usual warmth and confidence. "We're still hundreds of days away from reaching Earth."

Bucky grinned in reply while his arms slid around Tony's too-thin waist. He was careful not to squeeze, not wanting to aggravate Tony's ribs. "I believe in being prepared." He leaned in, nuzzling Tony's cheek. "Besides, it gives me something to look forward to," he whispered in Tony's ear.

"I wouldn't get ahead of myself if I were you, Mr. Space Pirate," Tony drawled in reply.

Bucky pulled back enough to meet Tony's gaze, raising a questioning eyebrow.

"You stole a spaceship—"

"Borrowed," Bucky interrupted. "We're in the process of returning it."

Tony rolled his eyes but clearly couldn't hold back an amused grin. "You _borrowed_ a spaceship from NASA. In all likelihood, you'll be behind bars as soon as we reach Earth — not taking me out on dates."

Bucky pretended to think on that for a couple of seconds before shaking his head.

"Nah," he replied with a mischievous grin, his flesh hand sliding in under the edge of Tony's t-shirt, just to feel the warmth of Tony's skin against his fingertips. "We did it to save you. Lockin' us up would be terribly bad PR."

"Well, I guess we shouldn't underestimate Ms. Potts' capabilities." Tony seemed to have decided that the conversation was best continued with his head resting on Bucky's shoulder, his arms tucked into the narrows space between them. "If anyone could talk you out of trouble, it's her."

It was clear that Tony was getting comfortable, the tension draining out of his body, slowly but surely. By the time they reached their quarters, he would probably be half-asleep already. The knowledge that Tony trusted Bucky enough to let his guard down around him made Bucky's stomach flutter.

"So, is that a yes?" Bucky asked, voice soft. "To the date?"

Tony's laugh was a soft puff of air against Bucky's neck. "Yes, you dork. I will go on a date with you."

Bucky grinned and placed a kiss against Tony's hair. "Come to bed?" he whispered.

"Before our first date? How _scandalous_ of you, doctor." Tony sounded both teasing and sleepy, which was a surprisingly adorable combination.

"Well, I _am_ a pirate," Bucky drawled, which earned him another laugh — a soft, happy laugh that made a lump appear in Bucky's throat and his grip around Tony tighten.

Bucky couldn't believe how lucky he was to have Tony in his arms. After everything they'd been through, it felt almost too good to be true.

"That you are." Tony straightened just enough to be able to give Bucky a smile and a gentle kiss. He was leaning against Bucky, content and relaxed, and Bucky felt his own worries ease, at least for the time being.

He knew they had a long way to go, both literally and figuratively — the journey back to Earth, shadows and nightmares to chase away, physical therapy for Tony, and a possible trial for Bucky — but for now, he could be happy with what he had. Tony was warm and safe in his arms, and Bucky had no intention of letting go.

For now, that was all that mattered. Right in that moment, that was all Bucky needed.

Tony yawned before burying his face against Bucky's neck. "Let's go to bed, Dread Pirate Barnes," he mumbled.

Bucky grinned, his heart soaring. "As you wish."

 

**Notes for the Chapter:**

> Okay, so maybe I lied when I said the epilogue would come on Friday. I got too impatient so SUPRISE, MY LOVELIES! Here's the final chapter!
> 
> Again, I want to thank [surgicalstainless](http://archiveofourown.org/users/surgicalstainless), [Potrix](http://archiveofourown.org/users/potrix), and [Shi_Toyu](http://archiveofourown.org/users/Shi_Toyu) for their support. Actually, you can thank Shi for that final scene, because I almost ended it after the one with Bucky and Steve. It's much better this way, though, so go give Shi all the love!
> 
> And yes, I admit that I panicked and ended the whole thing with a _Princess Bride_ reference because _why not_?
> 
> I hope you have enjoyed this journey, my darlings! I had so much fun writing this fic and I am terribly proud of it. Thank you for reading! <3


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